BMX on the Moon (1984)

You must ride your moon cycle across the surface of a choice of three moons, avoiding boulders, bouncing monsters, oncoming barrels and bombs dropped by overhead space ships. You are equipped with a moon gun, which fires simultaneously vertically and horizontally. Boulders can be shot to make jumping over them easier but firing into the ground creates craters, as do bombs dropped from above, these craters must be jumped over or a life is lost and the more difficult the moon the more rugged the landscape, so you'll have to be careful when firing.