A 48 hour game jam style contest could be pretty sweet. A set of jugdes would set up the contest and when it launches they release a secret keyword that should be reflected in the games participating.
A keyword could be "water" and then you had to somehow include water in the game. It could also be "artificial" and then you somehow would have to use that as a topic. It can also be a phrase you have to use. Example: "The future is bright" would require people to maybe look away from the always dark FPSC levels.
With secret keywords no one has a huge advantage from their pre-made levels and this usually works really well in short running contests where rapid development, iteration and creativity should rule.
edit: I might consider sponsoring a contest of this style actually
Name it FPSC Game Jam or something.
