diff --git a/ColourMeOKGame/Assets/Scripts/AccountUI.cs b/ColourMeOKGame/Assets/Scripts/AccountUI.cs
index 98a9e85..1c68236 100644
--- a/ColourMeOKGame/Assets/Scripts/AccountUI.cs
+++ b/ColourMeOKGame/Assets/Scripts/AccountUI.cs
@@ -67,6 +67,12 @@ public class AccountUI : MonoBehaviour
     /// </summary>
     private Button _secondaryActionButton;
 
+    /// <summary>
+    ///     either 'delete local data' or 'delete account'
+    ///     (in order of 'initial', and 'post' states, is hidden in 'after' state)
+    /// </summary>
+    private Button _tertiaryActionButton;
+
     /// <summary>
     ///     username text field
     /// </summary>
@@ -108,6 +114,9 @@ private void OnEnable()
         _secondaryActionButton = ui.Q<Button>("SecondaryActionButton");
         _secondaryActionButton.clicked += OnSecondaryActionButtonClick;
 
+        _tertiaryActionButton = ui.Q<Button>("TertiaryActionButton");
+        _tertiaryActionButton.clicked += OnTertiaryActionButtonClick;
+
         TransitionStateTo(State.NotSignedIn);
 
         if (state == State.UnassociatedState) throw new Exception("unreachable state");
@@ -120,7 +129,7 @@ private void OnEnable()
             _usernameField.value = username;
             _emailField.value = GameManager.Instance.Backend.GetUser().Email;
         });
-        GameManager.Instance.RegisterOnLocalPlayerDataChangeCallback(PopulateFields);
+        GameManager.Instance.RegisterOnLocalPlayerDataChangeCallback(OnLocalPlayerDataChangeCallback);
     }
 
     private void TransitionStateTo(State newState, bool keepAccompanyingText = false)
@@ -157,9 +166,11 @@ private void TransitionStateTo(State newState, bool keepAccompanyingText = false
 
                 _primaryActionButton.style.display = DisplayStyle.Flex;
                 _secondaryActionButton.style.display = DisplayStyle.Flex;
+                _tertiaryActionButton.style.display = DisplayStyle.Flex;
 
                 _primaryActionButton.text = "Continue \u2192";
                 _secondaryActionButton.text = "Forgot Password \u2192";
+                _tertiaryActionButton.text = "Delete Local Data \u2192";
                 break;
 
             case State.AfterContinue:
@@ -171,6 +182,7 @@ private void TransitionStateTo(State newState, bool keepAccompanyingText = false
 
                 _primaryActionButton.style.display = DisplayStyle.Flex;
                 _secondaryActionButton.style.display = DisplayStyle.Flex;
+                _tertiaryActionButton.style.display = DisplayStyle.None;
 
                 _primaryActionButton.text = "Retry Log In \u2192";
                 _secondaryActionButton.text = "Create an Account \u2192";
@@ -188,8 +200,10 @@ private void TransitionStateTo(State newState, bool keepAccompanyingText = false
 
                 _primaryActionButton.style.display = DisplayStyle.Flex;
                 _secondaryActionButton.style.display = DisplayStyle.None;
+                _tertiaryActionButton.style.display = DisplayStyle.Flex;
 
                 _primaryActionButton.text = "Sign Out \u2192";
+                _tertiaryActionButton.text = "Delete Account \u2192";
                 break;
 
             case State.UnassociatedState:
@@ -375,8 +389,6 @@ private void OnUsernameUpdateButtonClick()
                     _ => "An error occurred updating the username. Please try again."
                 };
             });
-
-        // TODO: update lpdata
     }
 
     /// <summary>
@@ -409,8 +421,6 @@ private void OnEmailUpdateButtonClick()
                     _ => "An error occurred updating the email. Please try again."
                 };
             });
-
-        // TODO: update lpdata
     }
 
     /// <summary>
@@ -513,7 +523,8 @@ private void OnPrimaryActionButtonClick()
 
             case State.UnassociatedState:
             default:
-                throw new ArgumentOutOfRangeException();
+                Debug.LogError($"tertiary button clicked in illogical state {state} (unreachable?)");
+                break;
         }
     }
 
@@ -537,7 +548,7 @@ private void OnSecondaryActionButtonClick()
                     return;
                 }
 
-                GameManager.Instance.Backend.ForgotPassword(_emailField.value, result =>
+                GameManager.Instance.Backend.ResetUserPassword(_emailField.value, result =>
                 {
                     _accompanyingText.style.display = DisplayStyle.Flex;
                     _accompanyingText.text =
@@ -591,6 +602,11 @@ private void OnSecondaryActionButtonClick()
                                 _accompanyingText.text = "Invalid credentials. Please try again.";
                                 break;
 
+                            case Backend.AuthenticationResult.UsernameAlreadyTaken:
+                                _accompanyingText.style.display = DisplayStyle.Flex;
+                                _accompanyingText.text = "Username already taken. Please try another.";
+                                break;
+
                             case Backend.AuthenticationResult.NonExistentUser:
                             case Backend.AuthenticationResult.AlreadyExistingUser:
                             case Backend.AuthenticationResult.GenericError:
@@ -605,10 +621,33 @@ private void OnSecondaryActionButtonClick()
                     _usernameField.value);
                 break;
 
-            case State.SignedIn:
             case State.UnassociatedState:
             default:
-                throw new ArgumentOutOfRangeException();
+                Debug.LogError($"tertiary button clicked in illogical state {state} (unreachable?)");
+                break;
+        }
+    }
+
+    private void OnTertiaryActionButtonClick()
+    {
+        switch (state)
+        {
+            // delete local data
+            case State.NotSignedIn:
+                PlayerPrefs.DeleteAll();
+                GameManager.Instance.Data.LoadFromTheWorld(GameManager.Instance.FireLocalPlayerDataChangeCallbacks);
+                break;
+
+            // delete user account
+            case State.SignedIn:
+                GameManager.Instance.Backend.DeleteUser();
+                break;
+
+            case State.AfterContinue:
+            case State.UnassociatedState:
+            default:
+                Debug.LogError($"tertiary button clicked in illogical state {state} (unreachable?)");
+                break;
         }
     }
 
@@ -616,12 +655,13 @@ private void OnSecondaryActionButtonClick()
     ///     populate the fields with the given username and email,
     ///     used as a callback to when local player data is changed
     /// </summary>
-    public void PopulateFields(LocalPlayerData data)
+    private void OnLocalPlayerDataChangeCallback(LocalPlayerData data)
     {
         Debug.Log(
-            $"populating AccountView fields with lkUsername={data.LastKnownUsername} and lkEmail={data.LastKnownEmail}");
+            $"updating AccountView ui with lkUsername={data.LastKnownUsername} and lkEmail={data.LastKnownEmail}");
         _usernameField.value = data.LastKnownUsername;
         _emailField.value = data.LastKnownEmail;
+        _header.text = $"Signed in as {data.LastKnownUsername}";
     }
 
     /// <summary>
diff --git a/ColourMeOKGame/Assets/Scripts/Backend.cs b/ColourMeOKGame/Assets/Scripts/Backend.cs
index b9a558f..a1443a4 100644
--- a/ColourMeOKGame/Assets/Scripts/Backend.cs
+++ b/ColourMeOKGame/Assets/Scripts/Backend.cs
@@ -22,6 +22,7 @@ public enum AuthenticationResult
         AlreadyAuthenticated,
         NonExistentUser,
         AlreadyExistingUser,
+        UsernameAlreadyTaken,
         InvalidEmail,
         InvalidCredentials,
         GenericError
@@ -308,69 +309,90 @@ private void AuthStateChanged(object sender, EventArgs eventArgs)
 
         if (registerUser)
         {
-            // register user
-            _auth.CreateUserWithEmailAndPasswordAsync(email, password)
-                .ContinueWithOnMainThread(createTask =>
+            // check if the username is already taken
+            _db.Child("users")
+                .OrderByChild("username")
+                .EqualTo(registeringUsername)
+                .GetValueAsync()
+                .ContinueWithOnMainThread(task =>
                 {
-                    if (createTask.IsCompletedSuccessfully)
-                    {
-                        // store username
-                        _db.Child("users")
-                            .Child(_user.UserId)
-                            .Child("username")
-                            .SetValueAsync(registeringUsername)
-                            .ContinueWithOnMainThread(setUsernameTask =>
-                            {
-                                if (setUsernameTask.IsCompletedSuccessfully)
-                                {
-                                    _username = registeringUsername;
-                                    callback(AuthenticationResult.Ok);
-                                }
-                                else
-                                {
-                                    Debug.LogError(setUsernameTask.Exception);
-                                    callback(AuthenticationResult.GenericError);
-                                }
-                            });
-                        return;
-                    }
-
-                    if (createTask.Exception?.InnerException == null)
+                    if (task.Exception != null)
                     {
+                        Debug.LogError(task.Exception);
                         callback(AuthenticationResult.GenericError);
                         return;
                     }
 
-                    var error = (AuthError)((FirebaseException)createTask.Exception.InnerException).ErrorCode;
-
-                    // ReSharper disable once SwitchStatementHandlesSomeKnownEnumValuesWithDefault
-                    switch (error)
+                    if (!task.IsCompletedSuccessfully || task.Result.ChildrenCount > 0)
                     {
-                        case AuthError.UserNotFound:
-                            callback(AuthenticationResult.NonExistentUser);
-                            return;
-
-                        case AuthError.InvalidEmail:
-                            callback(AuthenticationResult.InvalidEmail);
-                            return;
-
-                        case AuthError.WeakPassword:
-                        case AuthError.InvalidCredential:
-                            callback(AuthenticationResult.InvalidCredentials);
-                            return;
-
-                        case AuthError.AccountExistsWithDifferentCredentials:
-                        case AuthError.EmailAlreadyInUse:
-                            callback(AuthenticationResult.AlreadyExistingUser);
-                            return;
-
-                        case AuthError.Failure:
-                        default:
-                            Debug.LogError(error);
-                            Debug.LogError(createTask.Exception);
-                            callback(AuthenticationResult.GenericError);
-                            break;
+                        callback(AuthenticationResult.UsernameAlreadyTaken);
+                        return;
                     }
+
+                    // register user
+                    _auth.CreateUserWithEmailAndPasswordAsync(email, password)
+                        .ContinueWithOnMainThread(createTask =>
+                        {
+                            if (createTask.IsCompletedSuccessfully)
+                            {
+                                // store username
+                                _db.Child("users")
+                                    .Child(_user.UserId)
+                                    .Child("username")
+                                    .SetValueAsync(registeringUsername)
+                                    .ContinueWithOnMainThread(setUsernameTask =>
+                                    {
+                                        if (setUsernameTask.IsCompletedSuccessfully)
+                                        {
+                                            _username = registeringUsername;
+                                            callback(AuthenticationResult.Ok);
+                                        }
+                                        else
+                                        {
+                                            Debug.LogError(setUsernameTask.Exception);
+                                            callback(AuthenticationResult.GenericError);
+                                        }
+                                    });
+                                return;
+                            }
+
+                            if (createTask.Exception?.InnerException == null)
+                            {
+                                callback(AuthenticationResult.GenericError);
+                                return;
+                            }
+
+                            var error = (AuthError)((FirebaseException)createTask.Exception.InnerException).ErrorCode;
+
+                            // ReSharper disable once SwitchStatementHandlesSomeKnownEnumValuesWithDefault
+                            switch (error)
+                            {
+                                case AuthError.UserNotFound:
+                                    callback(AuthenticationResult.NonExistentUser);
+                                    return;
+
+                                case AuthError.InvalidEmail:
+                                    callback(AuthenticationResult.InvalidEmail);
+                                    return;
+
+                                case AuthError.WeakPassword:
+                                case AuthError.InvalidCredential:
+                                    callback(AuthenticationResult.InvalidCredentials);
+                                    return;
+
+                                case AuthError.AccountExistsWithDifferentCredentials:
+                                case AuthError.EmailAlreadyInUse:
+                                    callback(AuthenticationResult.AlreadyExistingUser);
+                                    return;
+
+                                case AuthError.Failure:
+                                default:
+                                    Debug.LogError(error);
+                                    Debug.LogError(createTask.Exception);
+                                    callback(AuthenticationResult.GenericError);
+                                    break;
+                            }
+                        });
                 });
             return;
         }
@@ -443,24 +465,28 @@ private void RetrieveUsernameWithCallback(Action<DatabaseTransactionResult, stri
             return;
         }
 
-        _db.Child("users").Child(_user.UserId).Child("username").GetValueAsync().ContinueWithOnMainThread(task =>
-        {
-            DatabaseTransactionResult result;
-            if (task.IsCompletedSuccessfully)
+        _db.Child("users")
+            .Child(_user.UserId)
+            .Child("username")
+            .GetValueAsync()
+            .ContinueWithOnMainThread(task =>
             {
-                result = DatabaseTransactionResult.Ok;
-                _username = task.Result.Value.ToString();
-                Debug.Log($"our username is {_username}");
-            }
-            else
-            {
-                result = DatabaseTransactionResult.Error;
-                _username = "Unknown";
-                Debug.LogError("failed to get username");
-            }
+                DatabaseTransactionResult result;
+                if (task.IsCompletedSuccessfully)
+                {
+                    result = DatabaseTransactionResult.Ok;
+                    _username = task.Result.Value.ToString();
+                    Debug.Log($"our username is {_username}");
+                }
+                else
+                {
+                    result = DatabaseTransactionResult.Error;
+                    _username = "Unknown";
+                    Debug.LogError("failed to get username");
+                }
 
-            callback(result, _username);
-        });
+                callback(result, _username);
+            });
     }
 
     /// <summary>
@@ -485,25 +511,45 @@ public void SignOutUser()
         _auth.SignOut();
     }
 
+    /// <summary>
+    ///     abstraction function to delete the user
+    /// </summary>
+    public void DeleteUser()
+    {
+        _user.DeleteAsync().ContinueWithOnMainThread(task =>
+        {
+            if (task.IsCompletedSuccessfully)
+            {
+                Debug.Log("user deleted");
+                SignOutUser();
+            }
+            else
+            {
+                Debug.LogError(task.Exception);
+            }
+        });
+    }
+
     /// <summary>
     ///     abstraction function for the user to reset their password
     /// </summary>
     /// <param name="email">the forgetful user's email lol</param>
     /// <param name="callback">callback function to be invoked after the password reset email is sent</param>
-    public void ForgotPassword(string email, Action<bool> callback)
+    public void ResetUserPassword(string email, Action<bool> callback)
     {
-        _auth.SendPasswordResetEmailAsync(email).ContinueWithOnMainThread(resetTask =>
-        {
-            if (resetTask.IsCompletedSuccessfully)
+        _auth.SendPasswordResetEmailAsync(email)
+            .ContinueWithOnMainThread(resetTask =>
             {
-                callback(true);
-            }
-            else
-            {
-                Debug.LogError(resetTask.Exception);
-                callback(false);
-            }
-        });
+                if (resetTask.IsCompletedSuccessfully)
+                {
+                    callback(true);
+                }
+                else
+                {
+                    Debug.LogError(resetTask.Exception);
+                    callback(false);
+                }
+            });
     }
 
     /// <summary>
@@ -522,7 +568,7 @@ public void GetRecentScores(Action<DatabaseTransactionResult, List<LocalPlayerDa
             callback(DatabaseTransactionResult.Unauthenticated, new List<LocalPlayerData.Score>(0));
             return;
         }
-        
+
         _db.Child("scores")
             .OrderByChild("timestamp")
             .LimitToLast(LocalPlayerData.MaxBestOnlineScores)
@@ -535,10 +581,9 @@ public void GetRecentScores(Action<DatabaseTransactionResult, List<LocalPlayerDa
                     callback(DatabaseTransactionResult.Error, new List<LocalPlayerData.Score>(0));
                     return;
                 }
-                
+
                 var scores = new List<LocalPlayerData.Score>();
                 foreach (var child in task.Result.Children)
-                {
                     try
                     {
                         var score = new LocalPlayerData.Score(child.Value as Dictionary<string, object>);
@@ -548,7 +593,6 @@ public void GetRecentScores(Action<DatabaseTransactionResult, List<LocalPlayerDa
                     {
                         Debug.LogError($"{e}\n{child.GetRawJsonValue()}");
                     }
-                }
 
                 callback(DatabaseTransactionResult.Ok, scores);
                 GameManager.Instance.FireLocalPlayerDataChangeCallbacks(GameManager.Instance.Data);
@@ -562,7 +606,7 @@ public void GetRecentScores(Action<DatabaseTransactionResult, List<LocalPlayerDa
     ///     callback function that takes in a <c>DatabaseTransactionResult</c> enum and a
     ///     <c>List&lt;LocalPlayerData.Score&gt;</c>
     /// </param>
-    public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData.Score>> callback)
+    private void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData.Score>> callback)
     {
         if (!Status.Equals(FirebaseConnectionStatus.Connected)) return;
 
@@ -571,7 +615,7 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
             callback(DatabaseTransactionResult.Unauthenticated, new List<LocalPlayerData.Score>(0));
             return;
         }
-        
+
         _db.Child("scores")
             .OrderByChild("avgPerceivedAccuracy")
             .LimitToLast(LocalPlayerData.MaxBestOnlineScores)
@@ -584,10 +628,9 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
                     callback(DatabaseTransactionResult.Error, new List<LocalPlayerData.Score>(0));
                     return;
                 }
-                
+
                 var scores = new List<LocalPlayerData.Score>();
                 foreach (var child in task.Result.Children)
-                {
                     try
                     {
                         var score = new LocalPlayerData.Score(child.Value as Dictionary<string, object>);
@@ -597,7 +640,6 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
                     {
                         Debug.LogError(e);
                     }
-                }
 
                 callback(DatabaseTransactionResult.Ok, scores);
                 GameManager.Instance.FireLocalPlayerDataChangeCallbacks(GameManager.Instance.Data);
@@ -651,10 +693,10 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
     {
         GetRecentScores((recentRes, recentScores) =>
         {
-            if (recentRes == DatabaseTransactionResult.Error)
+            if (recentRes != DatabaseTransactionResult.Ok)
             {
                 Debug.Log("failed to get recent scores");
-                callback(DatabaseTransactionResult.Error, 0f);
+                callback(recentRes, 0f);
                 return;
             }
 
@@ -664,10 +706,10 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
 
             GetBestScores((bestRes, bestScores) =>
             {
-                if (bestRes == DatabaseTransactionResult.Error)
+                if (bestRes != DatabaseTransactionResult.Ok)
                 {
                     Debug.Log("failed to get recent scores");
-                    callback(DatabaseTransactionResult.Error, 0f);
+                    callback(recentRes, 0f);
                     return;
                 }
 
@@ -687,7 +729,30 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
     public void UpdateUserRating(
         Action<DatabaseTransactionResult> callback)
     {
-        throw new NotImplementedException();
+        if (!Status.Equals(FirebaseConnectionStatus.Connected)) return;
+        
+        if (_user == null)
+        {
+            callback(DatabaseTransactionResult.Unauthenticated);
+            return;
+        }
+        
+        _db.Child("users")
+            .Child(_user.UserId)
+            .Child("rating")
+            .SetValueAsync(GameManager.Instance.Data.CalculateUserRating())
+            .ContinueWithOnMainThread(task =>
+            {
+                if (task.IsCompletedSuccessfully)
+                {
+                    callback(DatabaseTransactionResult.Ok);
+                }
+                else
+                {
+                    Debug.LogError(task.Exception);
+                    callback(DatabaseTransactionResult.Error);
+                }
+            });
     }
 
     /// <summary>
@@ -729,6 +794,8 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
                 {
                     if (task.IsCompletedSuccessfully)
                     {
+                        GameManager.Instance.Data.LastKnownEmail = newValue;
+                        GameManager.Instance.FireLocalPlayerDataChangeCallbacks(GameManager.Instance.Data);
                         callback(DatabaseTransactionResult.Ok);
                     }
                     else
@@ -740,12 +807,17 @@ public void GetBestScores(Action<DatabaseTransactionResult, List<LocalPlayerData
                 break;
 
             case UserAccountDetailTargetEnum.Username:
-                _db.Child("users").Child(_user.UserId).Child("username").SetValueAsync(newValue)
+                _db.Child("users")
+                    .Child(_user.UserId)
+                    .Child("username")
+                    .SetValueAsync(newValue)
                     .ContinueWithOnMainThread(task =>
                     {
                         if (task.IsCompletedSuccessfully)
                         {
                             _username = newValue;
+                            GameManager.Instance.Data.LastKnownUsername = newValue;
+                            GameManager.Instance.FireLocalPlayerDataChangeCallbacks(GameManager.Instance.Data);
                             callback(DatabaseTransactionResult.Ok);
                         }
                         else
diff --git a/ColourMeOKGame/Assets/Scripts/Colorimetry.cs b/ColourMeOKGame/Assets/Scripts/Colorimetry.cs
index fd8ad44..f6c585e 100644
--- a/ColourMeOKGame/Assets/Scripts/Colorimetry.cs
+++ b/ColourMeOKGame/Assets/Scripts/Colorimetry.cs
@@ -59,16 +59,16 @@ public static DeltaLabChE CalculateDistance(Color template, Color response)
 
         // https://en.wikipedia.org/wiki/Oklab_color_space#Color_differences
         // ... "The perceptual color difference in Oklab is calculated as the Euclidean
-        // ...      distance between the (L, a, b) coordinates."
+        // ... distance between the (L, a, b) coordinates."
         // https://github.com/svgeesus/svgeesus.github.io/blob/master/Color/OKLab-notes.md#color-difference-metric
         // ... ΔL = L1 - L2
-        // ... C1 = √(a1² + b1²)    -> chroma values
-        // ... C2 = √(a2² + b2²)    -> chroma values
-        // ... ΔC = C1 - C2         -> chroma difference
+        // ... C1 = √(a1² + b1²)
+        // ... C2 = √(a2² + b2²)
+        // ... ΔC = C1 - C2
         // ... Δa = a1 - a2
         // ... Δb = b1 - b2
-        // ... ΔH = √(Δa² + Δb² - ΔC²)      -> hue difference
-        // ... ΔE = √(ΔL² + ΔC² + ΔH²)    -> final difference
+        // ... ΔH = √(Δa² + Δb² - ΔC²)
+        // ... ΔE = √(ΔL² + ΔC² + ΔH²)
 
         float l1, a1, b1, l2, a2, b2;
         (l1, a1, b1) = (templateOklab.L, templateOklab.a, templateOklab.b);
@@ -117,6 +117,7 @@ public static Color RawLchToColor(double lightness, double chroma, double hue)
     /// <param name="x">the linear srgb value to transform</param>
     /// <returns>the non-linear srgb value</returns>
     // https://bottosson.github.io/posts/colorwrong/#what-can-we-do%3F (no licence specified)
+    // ReSharper disable once MemberCanBePrivate.Global
     public static double srgb_nonlinear_transform_f(double x)
     {
         if (x >= 0.0031308d)
@@ -130,6 +131,7 @@ public static double srgb_nonlinear_transform_f(double x)
     /// <param name="x">the non-linear srgb value to transform</param>
     /// <returns>the linear srgb value</returns>
     // https://bottosson.github.io/posts/colorwrong/#what-can-we-do%3F (no licence specified)
+    // ReSharper disable once MemberCanBePrivate.Global
     public static double srgb_nonlinear_transform_f_inv(double x)
     {
         if (x >= 0.04045d)
@@ -141,6 +143,7 @@ public static double srgb_nonlinear_transform_f_inv(double x)
     ///     clips a colour to the sRGB gamut while preserving chroma
     /// </summary>
     // https://bottosson.github.io/posts/gamutclipping/ (MIT)
+    // ReSharper disable once MemberCanBePrivate.Global
     public static RGB gamut_clip_preserve_chroma(RGB rgb)
     {
         if (rgb is { r: < 1 and > 0, g: < 1 and > 0, b: < 1 and > 0 })
@@ -171,6 +174,7 @@ public static RGB gamut_clip_preserve_chroma(RGB rgb)
     ///     a and b must be normalized so a^2 + b^2 == 1
     /// </summary>
     // https://bottosson.github.io/posts/gamutclipping/ (MIT)
+    // ReSharper disable once MemberCanBePrivate.Global
     public static float find_gamut_intersection(
         float a,
         float b,
@@ -307,6 +311,7 @@ public static Lab linear_srgb_to_oklab(RGB c)
     }
 
     // https://bottosson.github.io/posts/oklab/#converting-from-linear-srgb-to-oklab (public domain)
+    // ReSharper disable once MemberCanBePrivate.Global
     public static RGB oklab_to_linear_srgb(Lab c)
     {
         var interimL = c.L + 0.3963377774f * c.a + 0.2158037573f * c.b;
diff --git a/ColourMeOKGame/Assets/Scripts/GameManager.cs b/ColourMeOKGame/Assets/Scripts/GameManager.cs
index 74cf866..8ce1299 100644
--- a/ColourMeOKGame/Assets/Scripts/GameManager.cs
+++ b/ColourMeOKGame/Assets/Scripts/GameManager.cs
@@ -175,12 +175,14 @@ public void SignalGameEnd(List<Gameplay.RoundInfo> playedRounds)
         var historicalLightnessAcc = 0f;
         var historicalChromaAcc = 0f;
         var historicalHueAcc = 0f;
+        var historicalRounds = 0;
 
         foreach (var localScore in _data.RecentLocalScores)
         {
             historicalLightnessAcc += localScore.AvgLightnessAccuracy;
             historicalChromaAcc += localScore.AvgChromaAccuracy;
             historicalHueAcc += localScore.AvgHueAccuracy;
+            historicalRounds += localScore.NoOfRounds;
         }
 
         foreach (var onlineScore in _data.RecentOnlineScores)
@@ -188,6 +190,7 @@ public void SignalGameEnd(List<Gameplay.RoundInfo> playedRounds)
             historicalLightnessAcc += onlineScore.AvgLightnessAccuracy;
             historicalChromaAcc += onlineScore.AvgChromaAccuracy;
             historicalHueAcc += onlineScore.AvgHueAccuracy;
+            historicalRounds += onlineScore.NoOfRounds;
         }
 
         foreach (var onlineScore in _data.BestOnlineScores)
@@ -195,14 +198,19 @@ public void SignalGameEnd(List<Gameplay.RoundInfo> playedRounds)
             historicalLightnessAcc += onlineScore.AvgLightnessAccuracy;
             historicalChromaAcc += onlineScore.AvgChromaAccuracy;
             historicalHueAcc += onlineScore.AvgHueAccuracy;
+            historicalRounds += onlineScore.NoOfRounds;
         }
 
+        historicalLightnessAcc /= historicalRounds;
+        historicalChromaAcc /= historicalRounds;
+        historicalHueAcc /= historicalRounds;
+
         // calculate round averages
-        var roundLightnessAcc = 0d;
-        var roundChromaAcc = 0d;
-        var roundHueAcc = 0d;
-        var roundPerceivedAcc = 0d;
-        
+        var gameLightnessAcc = 0d;
+        var gameChromaAcc = 0d;
+        var gameHueAcc = 0d;
+        var gamePerceivedAcc = 0d;
+
         var templateColour = Color.clear;
         var responseColour = Color.clear;
         var roundNumber = 1;
@@ -211,58 +219,69 @@ public void SignalGameEnd(List<Gameplay.RoundInfo> playedRounds)
                          responseColour = round.ResponseColour)))
         {
             var dLCh = Colorimetry.CalculateLChSimilarityPercentage(distance);
-            
+
             Debug.Log(
                 $"processing round: template={templateColour}, response={responseColour} (dL%={dLCh.L}, dC%={dLCh.C}, dh%={dLCh.h}, dEok={distance.dE:F})");
 
-            roundLightnessAcc += Math.Clamp(dLCh.L * 100d, 0d, 100d);
-            roundChromaAcc += Math.Clamp(dLCh.C * 100d, 0d, 100d);
-            roundHueAcc += Math.Clamp(dLCh.h * 100d, 0d, 100d);
-            roundPerceivedAcc += Math.Clamp((100d - distance.dE) * 100d, 0d, 100d);
+            var roundLightnessAcc = Math.Clamp(dLCh.L * 100d, 0d, 100d);
+            var roundChromaAcc = Math.Clamp(dLCh.C * 100d, 0d, 100d);
+            var roundHueAcc = Math.Clamp(dLCh.h * 100d, 0d, 100d);
+            var roundPerceivedAcc = Math.Clamp((100d - distance.dE) * 100d, 0d, 100d);
+
+            gameLightnessAcc += roundLightnessAcc;
+            gameChromaAcc += roundChromaAcc;
+            gameHueAcc += roundHueAcc;
+            gamePerceivedAcc += roundPerceivedAcc;
 
             var showcaseTemplate = ui.UI.Q<VisualElement>($"ShowcasePair{roundNumber}TemplateColour");
             var showcaseResponse = ui.UI.Q<VisualElement>($"ShowcasePair{roundNumber}ResponseColour");
             var showcaseInfo = ui.UI.Q<Label>($"ShowcasePair{roundNumber}Info");
 
-            if (showcaseTemplate == null || showcaseResponse == null || showcaseInfo == null)
+            if (!(showcaseTemplate == null || showcaseResponse == null || showcaseInfo == null))
+            {
+                showcaseTemplate.style.backgroundColor = templateColour;
+                showcaseResponse.style.backgroundColor = responseColour;
+                showcaseInfo.text =
+                    $"{roundLightnessAcc:N0}% {roundChromaAcc:N0}% {roundHueAcc:N0}% ({roundPerceivedAcc:N0}%)";
+            }
+            else
             {
                 Debug.LogError($"showcase pair {roundNumber} not found");
-                roundNumber++;
-                continue;
             }
 
-            showcaseTemplate.style.backgroundColor = templateColour;
-            showcaseResponse.style.backgroundColor = responseColour;
-            showcaseInfo.text = $"{roundLightnessAcc:F}% {roundChromaAcc:F}% {roundHueAcc:F}% ({roundPerceivedAcc:F}%)";
-
-            roundNumber++;
+            roundNumber++; // used for ui querying
         }
 
-        roundLightnessAcc /= Gameplay.RoundsPerGame;
-        roundChromaAcc /= Gameplay.RoundsPerGame;
-        roundHueAcc /= Gameplay.RoundsPerGame;
-        roundPerceivedAcc /= Gameplay.RoundsPerGame;
+        gameLightnessAcc /= Gameplay.RoundsPerGame;
+        gameChromaAcc /= Gameplay.RoundsPerGame;
+        gameHueAcc /= Gameplay.RoundsPerGame;
+        gamePerceivedAcc /= Gameplay.RoundsPerGame;
 
-        var roundAcc = (roundLightnessAcc + roundChromaAcc + roundHueAcc + roundPerceivedAcc + roundPerceivedAcc) / 5;
+        // NOTE: this is NOT equiv to user rating, this is just a per-game accuracy score
+        // all that math is done in LocalPlayerData.CalculateUserRating
+        var gameAccuracy = (gameLightnessAcc + gameChromaAcc + gameHueAcc + gamePerceivedAcc) / 4;
 
         // make comparison texts
-        var lAccDeltaText = (roundLightnessAcc > historicalLightnessAcc ? "+" : "-") +
-                            Math.Abs(roundLightnessAcc - historicalLightnessAcc).ToString("P");
-        var cAccDeltaText = (roundChromaAcc > historicalChromaAcc ? "+" : "-") +
-                            Math.Abs(roundChromaAcc - historicalChromaAcc).ToString("P");
-        var hAccDeltaText = (roundHueAcc > historicalHueAcc ? "+" : "-") +
-                            Math.Abs(roundHueAcc - historicalHueAcc).ToString("P");
+        var lAccDeltaText = (gameLightnessAcc > historicalLightnessAcc ? "+" : "-") +
+                            Math.Abs(gameLightnessAcc - historicalLightnessAcc).ToString("F2");
+        var cAccDeltaText = (gameChromaAcc > historicalChromaAcc ? "+" : "-") +
+                            Math.Abs(gameChromaAcc - historicalChromaAcc).ToString("F2");
+        var hAccDeltaText = (gameHueAcc > historicalHueAcc ? "+" : "-") +
+                            Math.Abs(gameHueAcc - historicalHueAcc).ToString("F2");
 
         var score = new LocalPlayerData.Score(DateTime.Now,
             playedRounds.Count,
-            (float)roundLightnessAcc,
-            (float)roundChromaAcc,
-            (float)roundHueAcc,
-            (float)roundPerceivedAcc);
+            (float)gameLightnessAcc,
+            (float)gameChromaAcc,
+            (float)gameHueAcc,
+            (float)gamePerceivedAcc);
 
+        var oldRating = _data.CalculateUserRating();
         _data.RegisterLocalScore(score);
         FireLocalPlayerDataChangeCallbacks(Instance.Data);
 
+        Debug.Log("submitting score to backend");
+
         Backend.SubmitScore(score,
             submitRes =>
             {
@@ -301,14 +320,19 @@ public void SignalGameEnd(List<Gameplay.RoundInfo> playedRounds)
 
         void TransitionToResultsView(float rating)
         {
-            var ratingText = rating >= 0 ? $"\nYour rating is {rating:F}" : "\nYour rating could not be calculated.";
+            Debug.Log("signal GameManager-UIManager transition to results view");
+            
+            var ratingDifferenceDescriptor = oldRating > rating ? "decreased" : "increased";
+            var ratingText = rating >= 0
+                ? $"\nYour rating has {ratingDifferenceDescriptor} by {Math.Abs(rating - oldRating):F2}."
+                : "\nYour rating could not be calculated.";
 
             // build the result text and show the results view
             ui.UI.Q<Label>("ResultsText").text = string.Join(Environment.NewLine, $"Over {playedRounds.Count} rounds,",
-                $"you were {roundAcc} accurate.", "",
-                $"Lightness was {roundLightnessAcc:P}% accurate. ({lAccDeltaText} from your average)",
-                $"Chroma was {roundChromaAcc:P}% accurate. ({cAccDeltaText} from your average)",
-                $"Hue was {roundHueAcc:P}% accurate. ({hAccDeltaText} from your average)") + ratingText;
+                $"you were {gameAccuracy} accurate.", "",
+                $"Lightness was {gameLightnessAcc:F2}% accurate. ({lAccDeltaText} from your average)",
+                $"Chroma was {gameChromaAcc:F2}% accurate. ({cAccDeltaText} from your average)",
+                $"Hue was {gameHueAcc:F2}% accurate. ({hAccDeltaText} from your average)") + ratingText;
 
             ui.SetDisplayState(UIManager.DisplayState.ResultsView);
         }
diff --git a/ColourMeOKGame/Assets/Scripts/LocalPlayerData.cs b/ColourMeOKGame/Assets/Scripts/LocalPlayerData.cs
index 7ffa0a5..783bd60 100644
--- a/ColourMeOKGame/Assets/Scripts/LocalPlayerData.cs
+++ b/ColourMeOKGame/Assets/Scripts/LocalPlayerData.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Globalization;
+using System.Linq;
 using UnityEngine;
 
 public class LocalPlayerData
@@ -14,12 +15,11 @@ public class LocalPlayerData
     ///     maximum number of recent local scores to keep track of
     /// </summary>
     public const int MaxRecentLocalScores = 10;
-
+    
     /// <summary>
-    ///     queue of the best online scores,
-    ///     used in user rating calculation and accuracy display stats
+    ///     the gamma value used in the exponential user rating calculation
     /// </summary>
-    public Queue<Score> BestOnlineScores = new(20);
+    private const float ExponentialUserRatingGamma = 1.75f;
 
     /// <summary>
     ///     last known email used
@@ -34,13 +34,19 @@ public class LocalPlayerData
     /// <summary>
     ///     queue of the 10 most recent local scores
     /// </summary>
-    public Queue<Score> RecentLocalScores = new(10);
+    public readonly Queue<Score> RecentLocalScores = new(10);
 
     /// <summary>
     ///     queue of the 10 most recent online scores,
     ///     used in user rating calculation and accuracy display stats
     /// </summary>
-    public Queue<Score> RecentOnlineScores = new(10);
+    public readonly Queue<Score> RecentOnlineScores = new(10);
+
+    /// <summary>
+    ///     queue of the best online scores,
+    ///     used in user rating calculation and accuracy display stats
+    /// </summary>
+    public readonly Queue<Score> BestOnlineScores = new(20);
 
     /// <summary>
     ///     loads player data from player prefs and database
@@ -92,6 +98,10 @@ public void LoadFromTheWorld(Action<LocalPlayerData> callback)
                 Math.Clamp(c, 0f, 100f), Math.Clamp(h, 0f, 100f)));
         }
 
+        Debug.Log(
+            $"loaded lpdata from the local world ({LastKnownUsername} <{LastKnownEmail}> with RLS.Count={RecentLocalScores.Count}, ROS.Count={RecentOnlineScores.Count}");
+        callback(this);
+
         // load online scores
         RecentOnlineScores.Clear();
         GameManager.Instance.Backend.GetRecentScores((_, recentOnlineScores) =>
@@ -103,7 +113,7 @@ public void LoadFromTheWorld(Action<LocalPlayerData> callback)
             }
 
             Debug.Log(
-                $"loaded lpdata from the world ({LastKnownUsername} <{LastKnownEmail}> with RLS.Count={RecentLocalScores.Count}, ROS.Count={RecentOnlineScores.Count}");
+                $"loaded lpdata from the online world (now {LastKnownUsername} <{LastKnownEmail}> with RLS.Count={RecentLocalScores.Count}, ROS.Count={RecentOnlineScores.Count}");
 
             callback(this);
         });
@@ -130,7 +140,7 @@ public void SaveToTheWorld()
             idx++;
         }
 
-        Debug.Log("saved lpdata to playerprefs"); // online scores are already saved in the backend
+        Debug.Log("saved lpdata to player prefs"); // online scores are already saved in the backend
     }
 
     /// <summary>
@@ -149,7 +159,7 @@ public void RegisterLocalScore(Score score)
     /// <returns>the user rating (0-100f)</returns>
     public float CalculateUserRating()
     {
-        // user rating is like CHUNITHM's rating system
+        // user rating is like CHUNITHMs rating system
         // where best + recent scores are averaged out
         // in this case 20 best scores, and 10 recent scores are used
 
@@ -165,7 +175,7 @@ public float CalculateUserRating()
         var scores = 0;
         var totalRating = 0d;
 
-        foreach (var score in recentScores)
+        foreach (var score in recentScores.Take(10))
         {
             scores++;
             var dL = score.AvgLightnessAccuracy;
@@ -174,10 +184,10 @@ public float CalculateUserRating()
             var dE = Math.Sqrt(score.AvgLightnessAccuracy * score.AvgLightnessAccuracy
                                + score.AvgChromaAccuracy * score.AvgChromaAccuracy
                                + score.AvgHueAccuracy * score.AvgHueAccuracy);
-            totalRating = (dL + dC + dH + dE) / 4d;
+            totalRating += (dL + dC + dH + dE + dE) / 5d;
         }
 
-        foreach (var score in bestScores)
+        foreach (var score in bestScores.Take(20))
         {
             scores++;
             var dL = score.AvgLightnessAccuracy;
@@ -186,10 +196,18 @@ public float CalculateUserRating()
             var dE = Math.Sqrt(score.AvgLightnessAccuracy * score.AvgLightnessAccuracy
                                + score.AvgChromaAccuracy * score.AvgChromaAccuracy
                                + score.AvgHueAccuracy * score.AvgHueAccuracy);
-            totalRating = (dL + dC + dH + dE) / 4d;
+            totalRating += (dL + dC + dH + dE + dE) / 5d;
         }
-
-        return Math.Clamp((float)(totalRating / scores), 0f, 100f);
+        
+        scores = Math.Max(1, scores);
+        totalRating /= scores;
+        
+        var rawUserRating = Math.Clamp(totalRating, 0d, 100d);
+        var exponentialRating = 100d * Math.Pow(rawUserRating / 100d, ExponentialUserRatingGamma);
+        
+        Debug.Log($"locally calculated user rating: lin: {rawUserRating} -> exp: {exponentialRating}");
+        
+        return (float)exponentialRating;
     }
 
     public struct Score
@@ -218,7 +236,7 @@ public struct Score
         ///     average hue accuracy across all rounds (0-100)
         /// </summary>
         public readonly float AvgHueAccuracy;
-        
+
         /// <summary>
         ///     average perceived accuracy across all rounds (0-100)
         /// </summary>
@@ -232,7 +250,8 @@ public struct Score
         /// <param name="l">average lightness accuracy across all rounds (0-100)</param>
         /// <param name="c">average chroma accuracy across all rounds (0-100)</param>
         /// <param name="h">average hue accuracy across all rounds (0-100)</param>
-        /// /// <param name="e">average perceived accuracy across all rounds (0-100)</param>
+        /// ///
+        /// <param name="e">average perceived accuracy across all rounds (0-100)</param>
         public Score(DateTime timestamp = new(), int noOfRounds = 1, float l = 100.0f, float c = 100.0f,
             float h = 100.0f, float e = 100.0f)
         {
@@ -253,26 +272,36 @@ public Score(Dictionary<string, object> data)
         {
             // try to safely construct the score from a backend-provided dictionary
             // for each value, if it's not found, or not a valid value, throw an exception
-            
+
             if (!data.ContainsKey("timestamp") || data["timestamp"] is not long timestamp)
                 throw new ArgumentException("timestamp not found or invalid");
-            if (!data.ContainsKey("noOfRounds") || data["noOfRounds"] is not int noOfRounds)
+            if (!data.ContainsKey("noOfRounds") || data["noOfRounds"] is not long noOfRounds)
                 throw new ArgumentException("noOfRounds not found or invalid");
-            if (!data.ContainsKey("avgLightnessAccuracy") || data["avgLightnessAccuracy"] is not float avgLightnessAccuracy)
-                throw new ArgumentException("avgLightnessAccuracy not found or invalid");
-            if (!data.ContainsKey("avgChromaAccuracy") || data["avgChromaAccuracy"] is not float avgChromaAccuracy)
-                throw new ArgumentException("avgChromaAccuracy not found or invalid");
-            if (!data.ContainsKey("avgHueAccuracy") || data["avgHueAccuracy"] is not float avgHueAccuracy)
-                throw new ArgumentException("avgHueAccuracy not found or invalid");
-            if (!data.ContainsKey("avgPerceivedAccuracy") || data["avgPerceivedAccuracy"] is not float avgPerceivedAccuracy)
-                throw new ArgumentException("avgPerceivedAccuracy not found or invalid");
-            
+
+            var avgLightnessAccuracy = GetFloatyKey("avgLightnessAccuracy");
+            var avgChromaAccuracy = GetFloatyKey("avgChromaAccuracy");
+            var avgHueAccuracy = GetFloatyKey("avgHueAccuracy");
+            var avgPerceivedAccuracy = GetFloatyKey("avgPerceivedAccuracy");
+
             Timestamp = DateTimeOffset.FromUnixTimeSeconds(timestamp).DateTime;
-            NoOfRounds = noOfRounds;
+            NoOfRounds = (int)noOfRounds;
             AvgLightnessAccuracy = avgLightnessAccuracy;
             AvgChromaAccuracy = avgChromaAccuracy;
             AvgHueAccuracy = avgHueAccuracy;
             AvgPerceivedAccuracy = avgPerceivedAccuracy;
+
+            return;
+
+            float GetFloatyKey(string key)
+            {
+                if (!data.TryGetValue(key, out var possibleFloat)) throw new ArgumentException($"{key} not found");
+                return possibleFloat switch
+                {
+                    double f => (float)f,
+                    long l => l,
+                    _ => throw new ArgumentException($"{key} not a valid float")
+                };
+            }
         }
 
         /// <summary>
diff --git a/ColourMeOKGame/Assets/Scripts/SideViewUI.cs b/ColourMeOKGame/Assets/Scripts/SideViewUI.cs
index 9f53ffd..5375a03 100644
--- a/ColourMeOKGame/Assets/Scripts/SideViewUI.cs
+++ b/ColourMeOKGame/Assets/Scripts/SideViewUI.cs
@@ -105,6 +105,8 @@ private static void OnAccountButtonClicked()
     /// </summary>
     private void RenderFromPlayerData(LocalPlayerData data)
     {
+        Debug.Log("updating SideView > AccountSection with new player data");
+        
         // calculate averages from both recent local scores and online scores
         var totalLightnessAcc = 0f;
         var totalChromaAcc = 0f;
@@ -149,9 +151,9 @@ private void RenderFromPlayerData(LocalPlayerData data)
 
         // finally, set the labels
         _playerText.text = playerText;
+        _ratingText.text = $"{rating:F}";
         _lightnessAccuracyText.text = $"{lightnessAcc:F}";
         _chromaAccuracyText.text = $"{chromaAcc:F}";
         _hueAccuracyText.text = $"{hueAcc:F}";
-        _ratingText.text = $"{rating:F}";
     }
 }
\ No newline at end of file
diff --git a/ColourMeOKGame/Assets/UI/GameUI.uxml b/ColourMeOKGame/Assets/UI/GameUI.uxml
index 307d0f3..420f5f3 100644
--- a/ColourMeOKGame/Assets/UI/GameUI.uxml
+++ b/ColourMeOKGame/Assets/UI/GameUI.uxml
@@ -132,7 +132,7 @@
                 </ui:VisualElement>
             </ui:VisualElement>
             <ui:VisualElement name="ResultsView"
-                              style="flex-grow: 1; display: flex; margin-top: 3.25%; margin-right: 3.25%; margin-bottom: 3.25%; margin-left: 3.25%; justify-content: space-between;">
+                              style="flex-grow: 1; display: none; margin-top: 3.25%; margin-right: 3.25%; margin-bottom: 3.25%; margin-left: 3.25%; justify-content: space-between;">
                 <ui:VisualElement name="ColourShowcase"
                                   style="flex-grow: 1; background-color: rgb(255, 255, 255); border-top-left-radius: 8px; border-top-right-radius: 8px; border-bottom-right-radius: 8px; border-bottom-left-radius: 8px; padding-top: 2%; padding-right: 2%; padding-bottom: 2%; padding-left: 2%; margin-bottom: 2%; margin-top: 0; margin-right: 0; margin-left: 0;">
                     <ui:Label tabindex="-1" text="Templates" parse-escape-sequences="true"
@@ -202,7 +202,7 @@
                 <ui:ListView name="LeaderboardListView"/>
             </ui:VisualElement>
             <ui:VisualElement name="AccountView"
-                              style="flex-grow: 1; display: none; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; margin-top: 3.25%; margin-right: 3.25%; margin-bottom: 3.25%; margin-left: 3.25%; flex-direction: column; justify-content: space-between;">
+                              style="flex-grow: 1; display: flex; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; margin-top: 3.25%; margin-right: 3.25%; margin-bottom: 3.25%; margin-left: 3.25%; flex-direction: column; justify-content: space-between;">
                 <ui:Label tabindex="-1" text="You are not signed in." parse-escape-sequences="true"
                           display-tooltip-when-elided="true" name="AccountHeader"
                           style="font-size: 58px; -unity-font-style: normal;"/>
@@ -236,6 +236,9 @@
                                style="-unity-text-align: middle-center; margin-bottom: 1%; margin-right: 1%; margin-top: 1%; -unity-font-style: bold;"/>
                     <ui:Button text="Secondary Action Button →" parse-escape-sequences="true"
                                display-tooltip-when-elided="true" name="SecondaryActionButton"
+                               style="-unity-text-align: middle-center; margin-bottom: 1%; margin-right: 1%; margin-top: 1%; -unity-font-style: bold;"/>
+                    <ui:Button text="Tertiary Action Button →" parse-escape-sequences="true"
+                               display-tooltip-when-elided="true" name="TertiaryActionButton"
                                style="margin-top: 1%; margin-right: 1%; -unity-font-style: bold;"/>
                 </ui:VisualElement>
             </ui:VisualElement>