Alien Swarm

Alien Swarm is a four-player co-op action game with a top-down perspective and squad-level tactics. You lead a team of four IAF Marines through an off-world colony overrun by aliens, fighting to eradicate the infestation. The environments range from an icy planetary surface to a subterranean mining facility flooded with lava.

Squad tactics

You form a squad from four distinct Marine classes and plan your attacks together. An unlockable arsenal of over 40 weapons and equipment offers countless loadout configurations. You can gain levels to unlock persistent items, and choose from eight unique characters.

Tools and features

The game includes matchmaking, Steam Cloud, Steam Stats and 64 achievements. It also comes with a tile-based map generation tool, complete game code and mod tools.

The included code base features updates to the Source engine and SDK. Alien Swarm adds a third-person camera, depth of field, improved dynamic shadows and other gameplay additions to the engine.