From the introduction:
You are a machine; a thing of gears and springs, iron bars and lacquered wood, and more than anything else, steam. You're flying, miles above the surface of the Earth, on an airship you were designed to run and maintain. The airship, and its crew, was created by one solitary genius, who is even now sitting in the captain's chair. It's been over a hundred years since your creator has given you new orders... or spoken... or moved in any way, but you keep the airship going, even as time and nature tear it down. It's what you were made to do.
Steam and Storm is a one-shot RPG in which the players portray steam-powered robots, futilely attempting to keep their flying ship running, well after their captain is dead. There are two basic gameplay modes... "Wacky steampunk and explosion" and "grim, hopeless trudge into doom." Both use the same rules... you should all agree on what mode you will be playing.
Either way, the core of the game is clever justification: coming up with reasonable-sounding explanations for your wild perversions of mechanics, whether they are in service of zany robot antics and hilarity, or desperately clinging to a shred of familiarity in a meaningless, nihilistic existance.