Float your way through space, eating up stardust in an effort to become the biggest and baddest solar system in Crapl. The more stardust you consume, the larger you become, and the more celestial bodies begin to orbit your planet.
Move around with WASD, and perform a massive speed boost by left clicking. Any other solar systems caught in the orbits of your satellites will be blown to smithereens.
Take heed of explosive rings as well as the zone borders, both of which will result in a quick death.