It's an invasion from the Planet Mars! The players are the Martians determined to destroy the Pathetic Humans who are represented as Creeper cards. Martian Fluxx is chock-full of Flying Saucers, Giant Tripod War Machines, Tentacles, Ray Guns, a Mothership, and of course, a Space Modulator. Other Creepers include Germs, the Army, and the Important Human (required for the "Take Us To Your Leader" Goal).