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Alien Swarm header art

Alien Swarm

Co-operative multiplayer game and complete code base available for free.

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Developer
Publisher
Release
July 19, 2010
16 years and 18 days ago
Steam Reviews
Very Positive21,584 reviews94.8%

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Game contextLatest: IGF Team
ContextThe evidence factors used to assess whether this game belongs on IndieGame.Fan.Status
Notes
Latest Contributor: IGF TeamEdit notes
Updated: Jul 13, 2026Developer scaleThe operating scale of the game's developer.
Valve is a major platform holder and corporate-scale publisher.
Updated: Jul 13, 2026Publisher scaleThe operating scale of the game's publisher.
Valve is a major platform holder and corporate-scale publisher.
Updated: Jul 13, 2026Publisher statusHow the game's publishing relationship is classified.
Search Google: How is Alien Swarm and Valve funded?FundingThe known source of funding behind the game.
Search Google: Who controls the creative direction and IP for Alien Swarm and Valve?Creative controlWho appears to retain creative control of the game.
Updated: Jul 13, 2026Release statusWhether and how the game has been released.

Media

11 items

About the Game

Alien Swarm is a game and Source SDK release from a group of talented designers at Valve who were hired from the Mod community.
Available free of charge, the game thrusts players into an epic bug hunt featuring a unique blend of co-op play and squad-level tactics. With your friends, form a squad of four distinct IAF Marine classes. Plan your attack using an unlockable arsenal of weapons with countless loadout configurations against a wide variety of aliens. Blaze your way through an overrun, off-world colony, eradicating the alien infestation in environments ranging from the icy planet's surface, to a subterranean lava-flooded mining facility.
Along with the game get the complete code base for Alien Swarm that features updates to the Source engine as well as the SDK. Alien Swarm adds 3rd person camera, depth of field, improved dynamic shadows and a wide variety of gameplay additions to the Source engine.
  • Tactical, 4 player co-op action game with a top-down perspective
  • Complete game code and mod tools
  • Unlock persistent items by gaining levels
  • Over 40 weapons and equipment with countless loadout configurations
  • 4 unique classes and 8 unique characters
  • Matchmaking, Steam Cloud, Steam Stats
  • 64 achievements
  • Tile-based map generation tool
  • Powered by Source and Steam