Hopefully this meets your specifications - the ball is now smaller, is red & white, and performs a "wrap" when it goes off the top, bottom, left or right of the drawing area.
I have also improved the controls a little - before, only 1 key could be used at a time. Now you can use as many keys as you want, and the motion is smoother.
The controls are now -
Left & Right - X Position
Up & Down - Y Position
W & S - Z Position