Full loop from main menu to levels to end scene

Assets/Prefabs/GameController.prefab

@@ -45,5 +45,5 @@ MonoBehaviour:
   m_Name: 
   m_EditorClassIdentifier: 
   startScene: MainMenu
-  mainScene: Dev
+  mainScene: LevelDesign
-  endScene: MainMenu
+  endScene: ThanksScene

Assets/Scenes/MainMenu.unity

@@ -1387,11 +1387,6 @@ PrefabInstance:
       propertyPath: m_LocalEulerAnglesHint.z
       value: 0
       objectReference: {fileID: 0}
-    - target: {fileID: 4515361964050757685, guid: 875ca0f8a7a39ce459999ecf74b0fb3b,
-        type: 3}
-      propertyPath: mainScene
-      value: GameLogic
-      objectReference: {fileID: 0}
     - target: {fileID: 4515361964050757686, guid: 875ca0f8a7a39ce459999ecf74b0fb3b,
         type: 3}
       propertyPath: m_Name
@@ -1449,7 +1444,7 @@ RectTransform:
   m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
   m_AnchorMin: {x: 0, y: 0}
   m_AnchorMax: {x: 1, y: 1}
-  m_AnchoredPosition: {x: 82.546, y: -53.406006}
+  m_AnchoredPosition: {x: 82.54602, y: -53.406006}
   m_SizeDelta: {x: -165.09, y: -106.81}
   m_Pivot: {x: 0.5, y: 0.5}
 --- !u!114 &1703051055

Assets/Scripts/GameController.cs

@@ -36,4 +36,8 @@ public class GameController : MonoBehaviour
     public void Options(){
         Debug.Log("Clicked options");
     }
+
+    public void MainMenu(){
+        SceneManager.LoadScene(startScene);
+    }
 }

ProjectSettings/EditorBuildSettings.asset

@@ -14,6 +14,12 @@ EditorBuildSettings:
   - enabled: 1
     path: Assets/Scenes/GameLogic.unity
     guid: 6c735b8f44735c84789efdc5bc7c8d2d
+  - enabled: 1
+    path: Assets/Scenes/ThanksScene.unity
+    guid: b3991f64db889b744ba3668a4998424e
+  - enabled: 1
+    path: Assets/Scenes/LevelDesign.unity
+    guid: 4b213b8915c09ca49873cfadc143c61b
   m_configObjects:
     com.unity.input.settings: {fileID: 11400000, guid: 83b4255e269437642ad0474a7bdb56b5,
       type: 2}