Bounce Those Balls!
Run via Webstart (b18)
Not a game, exactly, but you can have fun creating various different balls and
watching them bounce around in a little sandbox. Try shrapnel balls and predator balls for the most fun.
Follow the simple interface. Fill in velocity, size, and color parameters, as well as checking off any of the 8 extra possibilities. Then click the add ball button, or press return. More hotkeys exist - read the text field within the program.