Glover separated the Jumpman sprite into two parts, the body and the feet. By examining which of these collided, the engine could determine which direction to move. For instance, if both the body and feet collided with the same color, it must be a wall, and the Jumpman should stop moving. If there was no collision with either his feet or body, Jumpman is unsupported and should fall down the screen. Variations on these allowed support for ramps, ropes, and other features.