Rework of UI + gamemanager instance

Assets/Scripts/GameManager.meta

@@ -0,0 +1,8 @@
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Assets/Scripts/GameManager/GameManager.cs

@@ -0,0 +1,15 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class GameManager : MonoBehaviour
+{
+    public static GameManager Instance;
+
+    private void Start()
+    {
+        if (Instance != this)
+            Destroy(Instance);
+        Instance = this;
+    }
+}

Assets/Scripts/GameManager/GameManager.cs.meta

@@ -0,0 +1,11 @@
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Assets/Scripts/PlacementSystem/PlacementManager.cs

@@ -12,7 +12,7 @@ public class TowerPlacementManager : MonoBehaviour
     /// Sender
     /// </summary>
     public static event Action<TowerPlacementManager> OnSpawnGridRequested;
-    public static TowerPlacementManager Singleton;
+    public static TowerPlacementManager Instance;
 
     // Section: Mouse
     private SlotManager CurrentSelectedSlot;
@@ -29,9 +29,9 @@ public class TowerPlacementManager : MonoBehaviour
 
     private void Start()
     {
-        if (Singleton != this)
+        if (Instance != this)
-            Destroy(Singleton);
+            Destroy(Instance);
-        Singleton = this;
+        Instance = this;
 
         OnSpawnGridRequested?.Invoke(this);
     }