Six steel balls roll down a vertical board to land in various scoring bins at the bottom. A wind-up mechanism releases them individually onto the topmost of a series of steps that you tilt manually. The longer you can control a ball's descent to land on more steps without rolling off into the gutters, the more points it scores. But don't spend too much time concentrating on one ball because the next one will drop at any second. As you become more proficient, you can shorten the time between balls from Beginner to Expert.