Co-operative multiplayer game and complete code base available for free.
Action / Shooter · 2010 · ~2.0 GB · See Steam store page
That One Thing
The corridor where the swarm pours in from both ends and your medic is the only reason anyone makes the extraction.
Alien Swarm is Valve's top-down co-op shooter: four marines drop into claustrophobic corridors, burn through ammo, and try not to get overrun by a hive that never stops coming. Classes matter — officer, special weapons, medic, tech — and so does not shooting your teammates when the hallway fills with parasites.
It shipped free on Steam in 2010 as a polished Source engine campaign with bots if friends are scarce. Missions are short, readable, and built around teamwork: cover the tech while they weld, keep the medic alive, and clear nests before the next wave spills out. The campaign is complete; there is no shop gate between you and the ending.
On PlayBound we list the original free Steam build. Controller support is partial on classic Swarm (console exec / Steam Input help); the community continuation Alien Swarm: Reactive Drop is the better pad-first option when you want official full controller support and a still-active multiplayer scene.
Checking…
Minimum Requirements
Windows 7 / Vista / XP · Pentium 4 3.0 GHz · 1 GB RAM (XP) / 2 GB (Vista+) · DX9 GPU 128 MB SM 2.0 · 2.5 GB storage
Recommended Requirements
Windows 7+ · Core 2 Duo 2.4 GHz · 2 GB RAM · DX9 GPU SM 3.0 (GeForce 7600 / Radeon X1600 or better) · 2.5 GB storage
Published by the game's own developers.
Yes. Valve released it free on Steam. PlayBound hands off to Steam for download and updates — there is no separate PlayBound-hosted package.
Alien Swarm is Valve's original 2010 campaign. Reactive Drop is the free community continuation with more content, active multiplayer, and official full controller support. Both are listed separately on PlayBound.
Partially. Classic Swarm often needs Steam Input or console commands. Reactive Drop ships official full controller support.
The campaign supports local play with bots. Online co-op needs Steam and a network connection.
Yes. Alien Swarm supports up to 4 players. You can host a game on your own PC. PlayBound Connect handles the setup: start a party with your friends, pick how you want to play, and everyone launches into the same game from the PlayBound launcher. It also supports co-op play. There is no subscription and no paid multiplayer tier.
Co-operative top-down shooter game available for free. An epic bug hunt featuring a unique blend of co-op play and squad-level tactics.
A free Source-engine RTS set in the Half-Life universe, playable on Steam.
Looking for the base game?
Alien Swarm has an overview, reviews, guides, and discussions covering every edition.