Alien Swarm

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Steam Deck support status:

Alien Swarm is a free top-down shoot-em-up for up to four co-op players, created by Black Cat Games after the company was bought up by Valve. Its complete source code is provided in the Source SDK.
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.
The game has been created as an sample project for Source modders, much like Team Fortress Classic was for GoldSrc.
Tile-based map tool
AS includes a new mapping tool with which levels can be quickly created. A set of tiles are provided, and they can be combined in different ways.
Source code
The source code for Alien Swarm will be released on Monday, July 19th, at the same time as the game. It will probably include Mac code.
Gallery
Content
- Alien Swarm
Confirm:(
as
) - Source 2007 shared (
hl2
) - Source shared (
hl2
) - Source 2009 engine branch