protected override void ReleaseReferences()
 {
     PauseGame();
     _isRun            = false;
     systemsHolder     = null;
     _systemController = null;
     _playerController = null;
     parameters        = null;
 }
 private void AssignSystems()
 {
     _systemController = new SystemController();
     foreach (Transform systemTr in systemsHolder)
     {
         var system = systemTr.GetComponent <GameSystem>();
         if (system == null)
         {
             continue;
         }
         system.Initialize();
         _systemController.AddSystem(system);
     }
 }