A ball sits on top of a tall, spinning tower of rings, and your job is to bring it down to the base. Stack Ball is a helix-style game played entirely with the mouse, layer after layer.
That is the one thing to avoid. The colored parts of the stack are your way down, while the black sections are where attempts end.
Only the mouse is needed, so one hand is enough. Watch how each ring rotates and act when a safe color is below the ball.
Speed feels great, but the tower keeps turning, and rushing makes it easy to miss a black tile sliding into place. Short bursts work better. Geometry Lite is another game on the site where that kind of timing decides everything.