GameMaster.cs

using UnityEngine;
using System.Collections;

public class GameMaster : MonoBehaviour {

    public static GameMaster gm;

    [SerializeField]
    private int maxLives = 3;
    private static int _remainingLives;
    public static int RemainingLives
    {
        get { return _remainingLives; }
    }

    void Awake()
    {
        if (gm == null)
        {
            gm = GameObject.FindGameObjectWithTag("GM").GetComponent<GameMaster>();
        }
    }
  
    public Transform playerPrefab;
    public Transform spawnPoint;
    public float spawnDelay = 2;
    public Transform spawnPrefab;
    public AudioClip respawnAudio;

    public CameraShake cameraShake;

    [SerializeField]
    private GameObject gameOverUI;

    void Start()
    {
        if (cameraShake == null)
        {
            Debug.LogError("No camera shake referenced in GameMaster");
        }

        _remainingLives = maxLives;

    }

    public void EndGame()
    {
        Debug.Log("GAME OVER");
        gameOverUI.SetActive(true);
    }

    public IEnumerator _RespawnPlayer()
    {
        AudioSource.PlayClipAtPoint(respawnAudio, new Vector3(spawnPoint.position.x, spawnPoint.position.y, spawnPoint.position.z), 1.0f);
        
        yield return new WaitForSeconds(spawnDelay);
        Instantiate(playerPrefab, spawnPoint.position, spawnPoint.rotation);
        GameObject clone = Instantiate(spawnPrefab, spawnPoint.position, spawnPoint.rotation) as GameObject;
        Destroy(clone, 3f);
        
    }

    public static void KillPlayer(Player player)
    {
        Destroy(player.gameObject);
        _remainingLives -= 1;
        if (_remainingLives <= 0)
        {
            gm.EndGame();
        }
        else
        {
            gm.StartCoroutine(gm._RespawnPlayer());
        }
    }

    public static void KillEnemy(Enemy enemy)
    {
        gm._KillEnemy(enemy);        
    }

    public void _KillEnemy(Enemy _enemy)
    {
       GameObject _clone = Instantiate(_enemy.deathParticles, _enemy.transform.position, Quaternion.identity) as GameObject;
        Destroy(_clone, 2f);
        cameraShake.Shake(_enemy.shakeAmt, _enemy.shakeLength);
        Destroy(_enemy.gameObject);
    }

}