Top similar games like Alien Swarm: Reactive Drop:

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

Purge the undead! Intense action-shooter with deep rpg elements, including upgradeable guns and armor, unique class skills, and class special abilities. Entire game can be played single player or as a 4-player online co-op game, including PvP events like Last Man Standing.

Warface is a contemporary MMO first person shooter with millions of fans around the world. It offers intense PvP modes, compelling PvE missions and raids that you can challenge with five diverse classes and a colossal customizable arsenal.

Play Evolve for free with Evolve Stage 2! Evolve Stage 2 is a next-generation free multiplayer shooter featuring addictive 4v1 gameplay. One player-controlled monster must evade and outsmart a team of four uniquely skilled hunters.

Codename CURE is a first person, co-operative zombie game with support for up to five players, providing dynamic, fast-paced zombie fragging with both objective, and survival-based missions.

Ready for the next generation of 3rd person shooters? Hazard Ops has zombies, monsters, robots, dinosaurs, mechs - pretty much anything you can point a gun at. Sink your teeth into this action-packed online shooter!

S.K.I.L.L. - Special Force 2 is a fast-paced, action-packed FPS shooter based on the Unreal Engine 3. The game features a wide range of game modes, tons of maps and a huge selection of weapons.

Orcs Must Die! Unchained takes the award-winning Orcs Must Die! action tower defense game to a whole new level with team-based gameplay! Bust skulls with your best pals in PvE co-op Survival, or put your teamwork to the real test in Sabotage Mode!

CS2D is a free fast-paced top-down multiplayer shooter. Featuring many different game modes, a built-in map editor and much more.

Onraid is a challenging 2D shooter game, where you are free to develop your own play style and tactics to destroy your enemies.

Black Squad is a free-to-play military first-person-shooter. Players can master their skills and show off their strategies with a wide range of game maps, modes, and weapons to choose from. Join thousands of FPS players worldwide in one of the most played games on Steam!

Deep within the SCP Foundation during a containment breach, many of the anomalies have bypassed security and escaped from their chambers - without peaceful intentions. Become site personnel, a re-containment agent, or an anomalous entity and fight to take control of or escape the facility!

Free to play shooter about the confrontation of two irreconcilable sides, represented by the government military housings and the armed hirelings. Try your hand at virtual battles with off-scale dynamics and hurricane gameplay in the spirit of the classical shooters.

AirMech® Strike is a fast paced Action-RTS game that can be played online competitively or cooperatively. Earn Kudos and Experience in battle and unlock a wide collection of AirMechs and Units while you practice the perfect strategy to emerge victorious!

Jump straight into combat in this official standalone FREE total conversion of Arma 3. Argo is a hardcore tactical first-person shooter, in which you fight across unrestricted terrain, and where a single bullet is all it takes. Master your craft to rank up and become (in)famous on the battlefield.

PlanetSide 2 is an all-out planetary war, where thousands of players battle as one across enormous continents. Utilize infantry, ground and air vehicles, and teamwork to destroy your enemies in this revolutionary first-person shooter on a massive scale.

The Ultimate BATTLE ROYALE! Sharpen your skills and kill everyone in your way as you hunt for guns, gear and glory in a massive battlefield where only ONE can be crowned the LAST MAN STANDING.

SEASON 6 NOW LIVE! The battle for Atlas continues as a hot (some might even say fiery) new freelancer enters the scene.

This edition packages weapon DLC from ten previous expansions as well new featured content.

Join the futuristic online open-world shooter where thousands of players scour a transformed Earth competing for alien technology.

BLOCKADE 3D! First Person Shooter in an editable procedural cubic world. A large arsenal of weapons, 4 teams at the same time and up to 32 players on one map. A large number of game modes!

America’s Army: Proving Grounds is the official game of the U.S. Army and part of the highly acclaimed America’s Army game series. This free military game focuses on small unit tactical maneuvers and puts you to the test in a wide variety of new America’s Army maps and AA fan favorites.

Guns and Robots is free to play online third person shooter. The game brings robot action with massive customization. Players get cartoony bright 3D graphics in attractive environments and challenge each other in open arenas.

This game is developed by an indy without any investment, meaning, every single penny came out of our own pocket. So it may disappoint you if you are looking for an FPS game that can compete with big boys. However, we did try our best. We hope you enjoy it as much as we enjoyed making it.