Not sure if any of you are aware...
But CG society puts on several awesome challenges per year. Their current challenge, called the Tornado Twins Game Challenge can be found here: http://challenge.cgsociety.org/game
Here is their description of the event:
"TornadoTwins; youtube’s number one game development channel, is partnering with CGSociety to host a global game challenge for the world’s top 3D artists. Accomplished 3D artists are enabled to turn their art into a complete first person shooter using FPS Control, the Twins’ plugin for the Unity Game Engine. It is unique in bringing artificial intelligence, weapons and interactive worlds to life, without the need of a development team. Participating artists will create up to 2 minutes of gameplay. The finished games will be exported to unity3d format for play in the browser, so that all competition viewers and judges can easily play the finished games."
Check it out!