According to a recent announcement by the Kirkland, Washington-based game developer Valve, a new version of Alien Swarm – a top-down shooting game developed in-house by Valve’s mod team – will be released today, July 19.

The new Alien Swarm will join the likes of Team Fortress, Counter-Strike and Day of Defeat, all of which were initially started off as mods by Valve; and subsequently converted into full games.

Alien Swarm was basically a total conversion mod for Unreal Tournament 2004, created in 2008 Black Cat Games, which was later hired by Valve and assigned the task of developing Left 4 Dead series and Portal 2. Black Cat apparently also worked out a way to come up with the new, highly impressive Alien Swarm version.

Alien Swarm is essentially a bug-hunting tactical shooter that will be completely free via Steam, Valve’s online distribution portal. The game boasts four-player co-op, a leveling system, and an armory of over 40 weapons.

In addition, since Valve is also updating the Source SDK, players who want to try putting levels together for the game, will have the requisite tools to do so.

Allowing the players a selection from eight different character skins, the squad-based tactical shooter features both single-player and multiplayer action, largely pertaining to the hunting down and slaughter alien bugs – with up to four players having the advantage of selecting from a quartet of IAF Marine classes.