FREE: Killing Floor (Steam Key)

The listing, Killing Floor (Steam Key) has ended.

The winner will receive a Steam Key for the game. Once activated, it will add the full game to your Steam account's library.

Here is the game's Steam store page: http://store.steampowered.com/app/1250/

To quote the description on that page:
Killing Floor is a Co-op Survival Horror FPS set in the devastated cities and countryside of England after a series of cloning experiments for the military goes horribly wrong. You and your friends are members of the military dropped into these locations with a simple mission: Survive long enough to cleanse the area of the failed experiments!

It's a very popular game, with over 1,000,000 copies sold, so it's quite likely you'll find people to play with online.

Obviously you need a Steam account to play. To activate Steam Keys, open the Steam application window, click "ADD A GAME...", then select "Activate a Product on Steam...".