Press the flag to start. The ball will follow your mouse, stamping as it goes. Press number keys 0-9 to change the size. 1 is 10%, 2 is 20%, and so on. 0 switches it back to 100%. For some reason, the smaller the size, the faster it follows your mouse... Press space to clear. Press the up and down arrows to switch the background from black to white. NEW MUSIC: Press the right arrow to switch to the next song. Press the left arrow to switch back.