добавил немного функционала

Assets/Scripts/GameSystem.cs

@@ -0,0 +1,56 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class GameSystem : MonoBehaviour
+{
+    public static GameSystem Instance { get; private set; }
+    public List<IGameComponent> gameComponents { get; private set; } = new List<IGameComponent>();
+
+    public void AddGameComponent(IGameComponent component)
+    {
+        if(!gameComponents.Contains(component))
+            gameComponents.Add(component);
+    }
+
+    void Awake()
+    {
+        Instance = this;
+    }
+
+    void Start()
+    {
+        GameSystem[] gameSystems = FindObjectsOfType<GameSystem>();
+        if(gameSystems.Length > 1)
+        {
+            Destroy(this.gameObject);
+            return;
+        }
+
+        DontDestroyOnLoad(this);
+    }
+
+    void Update()
+    {
+        for(int i = 0; i < gameComponents.Count; i++)
+            gameComponents[i].OnUpdate();
+    }
+
+    void FixedUpdate()
+    {
+        for(int i = 0; i < gameComponents.Count; i++)
+            gameComponents[i].OnFixedUpdate();
+    }
+
+    void LateUpdate()
+    {
+        for(int i = 0; i < gameComponents.Count; i++)
+            gameComponents[i].OnLateUpdate();
+    }
+
+    public void RemoveGameComponent(IGameComponent component)
+    {
+        if(gameComponents.Contains(component))
+            gameComponents.Remove(component);
+    }
+}