Found this in my news feeds, thought someone might be interested in testing it. Haven't played it, but the story sounds some what like Left 4 Dead adapted to a more traditional shooter game, and geared to the fast and furious frag fests.
The game engine is based on Cube 2, which has long been noted for its "In game level editing" feature, while the original Cube engine was more or less on par with DooM II + snazier graphics ability, Cube 2 is a modern beast capable of the good stuff.
There is such a thing as a Free and Open Source game with decent graphics, lol. Finding good graphic artist or modeller for free, is a different story...