Featuring Assault Rifles, Heat Tracking Guns, Sentry Guns, Flamethrowers and more. Alien Swarm can be played single-player or online co-operative multiplayer, with a strong emphasis on teamwork between the marines in both forms of play.
Alien Swarm is now on Steam, as a Source Mod.
guy2: the Steam version or UT version?
guy: what Steam version??
guy2: it just came out on Steam as a Source Mod
guy: well, like all urban dictionary definitions, i have to say something perverted now so-
guy2: ASS CLOWN!
guy: hey! i was gonna say that!