GameController.cs

using UnityEngine;
using UnityEngine.UI;
using System.Collections;

public class GameController : MonoBehaviour
{
    public GameObject[] hazards;
    public Vector2 spawnValues;
    public int hazardCount;
    public float spawnWait;
    public float startWait;
    public float waveWait;

    public Text scoreText;
    private int score;
    public Text restartText;
    public Text gameOverText;
    public Text healthText;
    public int health;


    private bool restart;
    private bool gameOver;

    void Start()
    {
        gameOver = false;
        restart = false;
        restartText.text = "";
        gameOverText.text = "";
        score = 0;
        UpdateScore();
        healthText.text = "Health: " + health;
        StartCoroutine(SpawnWaves());
    }

    void Update()
    {
        if (restart)
        {
            if (Input.GetKeyDown(KeyCode.R))
            {
                Application.LoadLevel(Application.loadedLevel);
            }
        }
    }
    IEnumerator SpawnWaves()
    {
        yield return new WaitForSeconds(startWait);
        while (true)
        {
            for (int i = 0; i < hazardCount; i++)
            {
                GameObject hazard = hazards[Random.Range(0, hazards.Length)];
                Vector2 spawnPosition = new Vector2(Random.Range(-spawnValues.x, spawnValues.x), spawnValues.y);
                Quaternion spawnRotation = Quaternion.identity;
                Instantiate(hazard, spawnPosition, spawnRotation);
                yield return new WaitForSeconds(spawnWait);
            }
            yield return new WaitForSeconds(waveWait);
            if (gameOver)
            {
                restartText.text = "Press 'R' to Restart";
                restart = true;
                break;
            }
        }


    }
    public void AddScore(int newScoreValue)
    {
        score += newScoreValue;
        UpdateScore();
    }
    void UpdateScore()
    {
        scoreText.text = "Score: " + score;
    }
    public void GameOver()
    {
        gameOverText.text = "Game Over!";
        gameOver = true;
    }


    public void UpdateHealth()
    {
        health -= 1;
        healthText.text = "Health: " + health;
        if (health <= 0)
        {
            GameOver();
        }
    }





}