Now, to come up with a theme.
RPG Element (i.e. a battle engine, or a world map, or an inventory system)
Black and White, (not even grey-scale, just B+W)
Vector based games (ala Asteroids, Tempest, Battlezone, or my fav "Major Havoc")
network games (simplistic, may require more time)
I believe highly in pseudorandom content generation. We'll discuss entries after coding is complete.
My system specs: P4 2.4Ghz, 768MB RAM, Radeon 9800, WinXP Pro, .Net 1.1, DX9c, Java 5, broadband internet. As long as I can execute it, I don't care what you use. Sorry, no SDL or Pythong. I could install Pythong and PyGame or whatever you want, but you'll have to link me directly to the downloads for my specs, I'm too lazy to find it on my own. I may whine if I see anything about "GPL" on the page you link me to.
Source code isn't required, but I'm thinking that if you do give it, I'll make a page with your source and your explanaition of the source. It'll be good for beginners on the site. In 3 hours, you won't write so much code that you won't be able to comment on every single line in complete detail later.
Prize? A nice, steaming plate of Rocky Mountain Oysters!
Three hours is plenty of time, if the scope of the project is clearly defined. Hell, I made Pong in under half an hour yesterday, without the use of game libraries or game makers, just straight Java.