void Update () {
		switch (gameState)
		{
			case gameStates.Playing:
				if (playerHealth.isAlive == false)
				{
					// update gameState
					gameState = gameStates.Death;

					// set the end game score
					gameOverScoreDisplay.text = mainScoreDisplay.text;

					// switch which GUI is showing		
					mainCanvas.SetActive (false);
					gameOverCanvas.SetActive (true);
				} else if (canBeatLevel && score>=beatLevelScore) {
					// update gameState
					gameState = gameStates.BeatLevel;

					// hide the player so game doesn't continue playing
					player.SetActive(false);

					// switch which GUI is showing			
					mainCanvas.SetActive (false);
					beatLevelCanvas.SetActive (true);
				}
				break;
			case gameStates.Death:
				backgroundMusic.volume -= 0.01f;
				if (backgroundMusic.volume<=0.0f) {
					AudioSource.PlayClipAtPoint (gameOverSFX,gameObject.transform.position);

					gameState = gameStates.GameOver;
				}
				break;
			case gameStates.BeatLevel:
				backgroundMusic.volume -= 0.01f;
				if (backgroundMusic.volume<=0.0f) {
					AudioSource.PlayClipAtPoint (beatLevelSFX,gameObject.transform.position);
					
					gameState = gameStates.GameOver;
				}
				break;
			case gameStates.GameOver:
				// nothing
				break;
		}

	}