It's a Martian Invasion-themed version of Fluxx! Just as Zombie Fluxx draws on all those classic Zombie movies for inspiration, Martian Fluxx is about all those great alien invasion stories going back to the original, the War of the Worlds.
Some of the Keepers you'll find in the Martian Fluxx: Mars, the Mothership, the Flying Saucer, the Tripod, the City, the Cow, the Ray Gun, the Space Suit, and the Tentacle.
The Tentacle? I hear you asking. How is that a good thing? All those other things sound like great Keepers but what's good about a tentacle? Well, they're great if you're a Martian... which is what we are in this game!
In Martian Fluxx, the players are invaders from Mars, and the Creepers are those pesky Pathetic Humans who are always getting in our way, keeping us from winning. Cows of course are Keepers because for Humans and Martians alike, they're good eating. There are actually two Cow Keepers in the game; if you have them both you can win with the Goal "Two All-Beef Earthlings."
The idea of making us the Martians came about as I realized the Martians are the ones who get all the cool stuff! Other cool Keepers you'll find include the Abduction Chamber (which you can hide your Pathetic Humans in), the Space Modulator and the Mind-Control Transmitter. And yes, you can use that Ray Gun to vaporize Pathetic Humans. (The Germs Creeper however is harder to get rid of...)