So, I got inspired and am planning to write a game about emotionally-driven heroes defending their town from great evils at the dawn of civilization. Three sessions. Player with the most glory at the end wins.
Dooms are decided by committee at the beginning of each session. The gamemastering duties go to whichever player suggested the Doom that faces you each evening, and they get called "Doom Master" for the duration.
More at my game chef thread.