Heads or Tails game

GreenfootImage Tails1 = new GreenfootImage("Tails1.png");
    GreenfootImage Tails2 = new GreenfootImage("Tails2.png");
    private int flipCoin = Greenfoot.getRandomNumber(2);
    /**
     * Act - do whatever the Tails wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        mouseHover();
        generate();
    }    
 
    private void generate()
    {
            if (flipCoin == 0)
            {
               getWorld().addObject(new HeadsCoin(),500,250);
               World world = getWorld();
               gameWorld myWorld = (gameWorld)world;
               HealthBar healthbar = myWorld.getHealthBar();
               healthbar.loseHealth();
            }
            if (flipCoin == 1)
            {
               getWorld().addObject(new TailsCoin(),500,250);
               World world = getWorld();
               gameWorld myWorld = (gameWorld)world;
               Counter counter = myWorld.getCounter();
               counter.addScore();
            }
    }

public class GameWorld extends World
{
    Actor btnFlip = new Button("Flip");
    Actor hiLiter = new HiLiter();
    Actor btnHeads = new Button("Heads");
    Actor btnTails = new Button("Tails");
    Counter counter = new Counter();
    HealthBar healthbar = new HealthBar();
    int choice;
    
    public GameWorld()
    {
        super(600, 400, 1);
        addObject(counter, 80, 100);
        addObject(healthbar, 80, 500);
        addObject(btnFlip, 300, 300);
        addObject(hiLiter, 120, 200);
        addObject(btnHeads, 120, 200);
        addObject(btnTails, 480, 200);
    }
    
    public void act()
    {
        if (Greenfoot.mouseClicked(btnFlip))
        {
            removeObjects(getObjects(HeadsCoin.class));
            removeObjects(getObjects(TailsCoin.class));
            int flipped = Greenfoot.getRandomNumber(2);
            Actor coin = flipped == 0 ? new HeadsCoin() : new TailsCoin();
            addObject(coin, 300, 100);
            if (flipped == choice) counter.addScore(); else healthbar.loseHealth();
        }
        if (Greeenfoot.mouseClicked(btnHeads))
        {
            hiLiter.setLocation(120, 200);
            choice = 0;
        }
        if (Greenfoot.mouseClickeΦ(btnTails))
        {
            hiLiter.setLocation(480, 200);
            choice = 1;
        }
    }
}