The user controls a trampoline. This trampoline can be moved across the bottom of the screen, horizontally. "Bob" jumps on this trampoline, and each time Bob hits the trampoline, he jumps higher than the previous time. On the top of the screen, there are some items that can be collected. When Bob hits the edge of the trampoline, he jumps to the side: you will have to move the trampoline to catch him the next time, because he will fall off and die otherwise. The objective is to collect a number of items at the top of the screen. When you have done so, the level is finished, and you proceed to the next level. If Bob falls on the ground (besides the trampoline), he dies. Bob has a number of lives; each time a level is finished, one extra life is added. If Bob has no lives left, the game is over.