We have mentioned In The Pit before - back when it was a 3-level Xbox 360 demo.
Described as "An 'audio-only' stealth action game", you are a monster hunting down unfortunate victims hurled into your pit by an evil king. It's a Grue simulator, basically.
The demo has been expanded into a full game, which will be one of the NXE Community Games launch titles. Check out the trailer. With your eyes closed.
In the Pit [XNA]