public class Player_1 extends Players
{
    /**
     * Act - do whatever the Player_1 wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act() 
    {
        Move();
        Hit();
        wrapAtEdge();
    }    

    public void Move()
    {
        if (Greenfoot.isKeyDown("w"))
        {
            move(3);
            setRotation(-90);
        }
        if (Greenfoot.isKeyDown("a"))
        {
            move(3);
            setRotation(180);
        }
        if (Greenfoot.isKeyDown("s"))
        {
            move(3);
            setRotation(90);
        }
        if (Greenfoot.isKeyDown("d"))
        {
            move(3);
            setRotation(0);
        }
    }

    public void Hit()
    {
        removeTouching(BlueCircle.class);
        OnePlayer oneplayer = (OnePlayer)getWorld();
        Counter counter = oneplayer.getCounter();
        counter.addScore();
    }

}

public class OnePlayer extends World
{
    Counter counter = new Counter();
    public OnePlayer()
    {    
        // Create a new world with 600x400 cells with a cell size of 1x1 pixels.
        super(600, 400, 1); 
        prepare();
    }
    
    public Counter getCounter()
    {
        return counter;
    }
    
    /**
     * Prepare the world for the start of the program. That is: create the initial
     * objects and add them to the world.
     */
    private void prepare()
    {
        Player_1 player_1 = new Player_1();
        addObject(player_1, getWidth()/2, getHeight()/2);
        addObject(counter, 0, 0);
        BlueCircle bluecircle = new BlueCircle();
        addObject(bluecircle, 494, 308);
        
        
    }
    
}

public class Counter extends Score
{
    int score = 0;
    public Counter()
    {
        setImage(new GreenfootImage("Score; " + score, 40, Color.BLACK, Color.WHITE));
    }
    public void act()
    {
        setImage(new GreenfootImage("Score; " + score, 40, Color.BLACK, Color.WHITE));
    }
    public void addScore()
    {
        score++;
    }
}