After you press the green flag to start the game, you'll be given a limited amount of time to hit as many heads with your hammer as possible. Move the hammer with your mouse, and hit heads by pushing the mouse button. If you like, post your best score in the comments, but be sure to say if you were playing in your browser or in scratch If you decide to change the behaviour of the heads, delete all but the first, change it until it works as you like it, then duplicate it several times, moving and sizing each duplicate as appropriate.