In the future, intergalactic mail delivery has taken on a novel form: the mail is packed into spheres and blasted into the void by giant cannons. Networks of gravity generators adjust the paths of the mail spheres and guide them to their destinations. In your role as gravity technician, you must plan out new routes between the mail cannons and space stations, navigating your way around asteroid fields, black holes, space pirates, and other hazards of deep space.
Energy fields and nebulas are common obstacles in space.