You play the game as a repair man equipped with a jetpack and an upwards firing plasma laser. Your mission is to repair all the leaking air pipes which supply the Colony research station on the surface of the Moon. Sounds simple enough, but now the caverns are inhabited by a number of alien lifeforms which will kill you if they touch you. Finally you must keep an eye on your ever decreasing air supply. You can refill from one of the big air tanks on the surface but it means breaking off your repairs. Your space suit tank can only hold so much air. Overfilling is deadly!