Alien Swarm

Alien Swarm is an overhead view tactical squad-based shooter for UT2K4. Set in the the distant future, the players take the role of a Commander in the Interstellar Armed Forces. They must guide their squad of marines through Swarm infested colonies, overrun bases and outposts, to achieve a variety of objectives. Featuring Assault Rifles, Heat Tracking Guns, Sentry Guns, Flamethrowers and more. Supports co-operative multiplayer.

Homepage
Debian based installation guide