Alien Swarm: Reactive Drop extends Alien Swarm, bringing more of everything: maps, aliens, game modes, guns... And most importantly Steam Workshop support.

• Tactical co-op for up to 8 players with a top-down perspective

• Steam Workshop support for community maps and challenges

• New co-operative campaigns

• Challenges: Modifications of the game, just like Mutations in Left 4 Dead 2

• PvP: Deathmatch, Gun Game, Instagib, and Team Deathmatch

• Singleplayer: Play with improved bots on all our official maps

• New Aliens: HL2 antlion guards and more

• New Weapons: Bulldog, Devastator, and Combat Rifle, with more to come

• Over 100 Steam achievements

• Leaderboards: compete with your friends for the fastest mission completion

• Improved spectating: see hacking minigames and mouse movements in real time