Alien Swarm is a third person, squad-based, 3D shooter. There are four classes; you control one marine, while the AI or other players in online play control the other three. The game bears a striking resemblance to the Space Hulk board game or its digital port, Alien Assault. Like Alien Assault, it is mission-based, with different goals for victory in each mission.
There is a Space Hulk Sergeant-like class and three classic RPG classes that you can play:
- Officer (Space Hulk Sergeant) -- Gives positive combat modifiers to the squad, akin to the Sergeants in Space Hulk.
- Special Weapons (warrior) -- Armed with a high damage minigun and access to other high damage weapons.
- Medic (cleric) -- Heals the squad.
- Tech (thief) -- Opens and seal doors, and aids in early enemy detection.
Since Alien Swarm only requires four players, it is easy to find people to play online. The game plays more like an arcade action, dungeon-crawler like Gauntlet than the more cerebrally strategic Alien Assault, and has the RPG element of leveling up. It is fast-paced and hectic; alien critter big and small try to overrun your squad as you lay down a rain of bullets, being careful to avoid friendly fire.
The existence of the medic makes the game somewhat less tense than Alien Assault, since the entire team can be healed. However, the class is necessary given the multiplayer nature of the game; in Alien Assault, you command the entire team, so the loss of one team member is unlikely to be critical. In Alien Swarm, you control only your own character, meaning that if you were to die, you'd have to sit out the rest of the battle -- up to ten minutes -- which would suck. The existence of the medic solves this problem.
Alien Swarm started as a mod for Unreal Tournament 2004 by Black Cat Games in 2004. The original developers were hired by Valve, and Alien Swarm was created as self-contained, free game. Being published by Valve, the game is polished and is offered as free only via Valve's digital distribution store, Steam. Steam accounts are free and you can optionally purchase other games.