Killing Floor is the evolution of an Unreal Tournament 2004 conversion that sees players teaming up to battle hordes of infected creatures rampaging through London. Players can either play offline or team up with up to five others in online co-op mode. It sounds a bit like Left 4 Dead, but in Killing Floor players can direct the flow of the undead using various tools, adding an element of strategy that's a great deal deeper that simply shooting until you're safe.
The game is now available for pre-purchase through Steam, where early orders get 25% off the retail price of $19.99. If the gameplay is half as exciting as the new trailer for the game seems to indicate, $15 is a paltry price to pay.