public void draw(Graphics g) {
		GameTool.drawBackground(g, ImageResource.getBackground());

		if (player != null) player.show(g); // show 

		for (Bullet bullet : bullets) bullet.show(g); 
		for (Enemy enemy : enemies) enemy.show(g); 
		for (EnemyBullet eb : eBullets) eb.show(g); 
	}