Add game manager

Scripts/Main.cs

@@ -6,11 +6,15 @@ public partial class Main : Node
 {
    [Export]
    public Array<PackedScene> Levels;
+   [Export]
+   public PackedScene GameManager;
 
    public void LoadLevel(int indexToLoad)
    {
       var sceneToLoad = Levels.ElementAt(indexToLoad);
       CallDeferred(nameof(DeferredGoToScene), sceneToLoad);
+      var gameManager = GameManager.Instantiate();
+      AddChild(gameManager);
    }
 
    public void LoadNextLevel(int currentSceneIndex)

Scripts/MainMenu.cs

@@ -16,13 +16,12 @@ public partial class MainMenu : Node2D
       var bgmPlayer = GetTree().Root.GetNode<BGMPlayer>("BgmPlayer");
       bgmPlayer.SetBGMFromFilepath("Audio/BGM/02 MovinOn.mp3");
       bgmPlayer.PlayBGM();
-      var main = GetTree().Root.GetNode<Main>("/root/Main");
-      main.LoadLevel(0);
    }
 
    private void OnStartButtonPressed()
    {
       _player.Play("FirstLevel");
+      var main = GetTree().Root.GetNode<Main>("/root/Main");
       Hide();
       _player.AnimationFinished += OnAnimationFinished;
    }