Mac must neutralise various single-screen vaults in this early platformer. He can climb ladders and safely fall any distance, as long as he lands on smooth ground. The puzzle aspect of the gameplay involves switches, which can remove walls, create floors and freeze obstacles. They must be pushed in the right order to allow access to parts of the room which contain other switches. A lack of air creates a time limit, with bonus points awarded for however much air is left when the screen is completed.