A sample game using Silverlight
Tim Heuer blogs about the experience of Terralever, a .NET shop who currently produce interactive games based on Flash. They wanted to see if Silverlight can be used to build the type of interactive games they have been building. The end-result is Zero Gravity. They even made their character, Lt. Bennett, "social network aware" so that you can add him to your Facebook, MySpace, and even Twitter.
Read more about it here -> silverlight: who needs inertia, introducing lt. bennett
About the game. I got to level 8 (teleportorama). I'm not sure if I hate the music though.