The player controls Harry the Ape who is attempting to climb a 150 floor tall office tower. The player can move up, left, and right, as the building scrolls vertically. The player must avoid closed windows, as they offer no handhold, and will cause your ape to fall. As the player ascends, they must avoid a zookeeper on a scaffold, falling bowling balls, earthquakes, and helicopters dropping nets. Occasionally a balloon will float up the left side of the building, and the player can hitch a ride on these to climb faster. The left side of the screen has a progress bar that shows how far the player has climbed the building. The player has one life to climb the building, and if they fall, they must restart.