Damnation is a steampunk shooter developed by Blue Omega Entertainment and published by Codemasters on May 2009, for PC, PlayStation 3 and Xbox 360. The game originally started as an Unreal Tournament 2004 mod and was entered into Epic Games first Make Something Unreal contest. The retail version retains much of the mod’s gameplay, including first and third person gameplay, acrobatic moves and spirit vision. [Info from Wikipedia]
Blue Omega tried to pitch their Unreal Mod to develop it into a commercial game and when they found a publisher interested in the project, the team worked hard to expand Damnation into a full title for the “next gen” consoles.
The original Damnation 2004 MOD can still be downloaded from the Beyond Unreal archive.
Thanks to Jason for the english corrections!