Steam app 563560 · updated 12 Sep 2026, 18:34 UTC
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.
718 hourly samples, with the daily peak drawn over them. Weekends are shaded.
117 months, January 2017 to September 2026. The highest number of people in the game at once, each month, on a time axis -- a gap in the record stays a gap.
The highest number of people in the game at once, each month. Four, because four is as far back as the source keeps anything finer than one figure a month.
31 days, each one the highest figure that day. The source keeps no hourly detail this far back. Weekends are shaded.
31 days as the curve, each the highest figure that day. Behind it, 438 hourly samples from 13 Aug, which is as far back as the source keeps every hour. Weekends are shaded.
12 days as the curve, each the highest figure that day. Behind it, 280 hourly samples. Each dip is a night. Weekends are shaded.
Alien Swarm: Reactive Drop was released on 20 Apr, 2017.
The main gameplay loop is using weapons to kill alien bugs. Aliens explode into blood and gore when killed. Bloodied human corpses can be found in some missions, but there is no graphic human dismemberment. Friendly fire with explosives can cause marines to break apart into cartoon "gibs". Profanity such as "shit" is used in voiced dialogue. Strong language is also used in some optional written content. Photosensitivity warning: There are some community-made missions that use a strobe light effect.
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| English | ● |
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| Portuguese - Brazil |
A blank audio cell means full audio was not marked in the returned language list.
198 achievements in total.
50 developer announcements, Sep 2022 to Apr 2026 · times in UTC
It's time once again for Alien Swarm: Reactive Drop's birthday. We're having a smaller one this year since a lot of our core contributors have been busy with other projects, but we've still got a lot of improvements to share and the usual…
Ben LubarEvery year, Valentines day is a time to be with friends and loved ones and reflect on your friendship and love. Well, not this year! In 2026, it's all about having simulated gun fights with friends and loved ones. Welcome to Steam PvP Fest…
Ben LubarHighlights Added a SynTek Residential themed main menu background. The camera feeds that display behind briefing have less static and are less distracting. Many guns are now more accurate while crouching. Weapons Weapon recoil has been…
Ben LubarA minor update has been released for Alien Swarm: Reactive Drop. Fixed a client crash in the Traitors game mode. Added a note in the Swarmopedia about the IAF Medical SMG's increased accuracy while crouching. Added a description for EC-02…
Patch notesFixed black bars appearing on the sides of the screen for screen resolutions with an aspect ratio wider than 16:9.Fixed traitor players showing as having 99 player kills in the scoreboard.Fixed buzzers bleeding red blood on the client.
Patch notesSpecial thanks to Dmitriy, Mithrand, jhheight, 法克尤尔马泽尔, and Grimowy for the majority of the changes in this update. New Game Mode: "Traitors!" Commander, As the human shield, the IAF has achieved great victories in countless battles against…
Ben LubarAdded rd_lobby_query_servers convar (default 0 until the problem with the Steam API is fixed) to disable server list queries, which are currently not being properly filtered to just Alien Swarm: Reactive Drop servers by the Steamworks…
Patch notesIt's that time of the year again. The anniversary of Alien Swarm: Reactive Drop's Steam release. As always, Alien Swarm: Reactive Drop is only possible due to contributions from community volunteers in the form of donations, code…
Ben LubarIt wouldn't be an Alien Swarm: Reactive Drop anniversary update without a shipload of fixes! Missions Jacob's Rest: Landing Bay: A crate in the welding tutorial room no longer allows bullets and grenades to pass through. Jacob's Rest: Deima…
Ben LubarIt's 2025, and to start the year off we have a pile of community-requested fixes! Commanders searching for anomalous materials together may find them quicker. Added convar rd_chat_item_messages to opt out of messages about players obtaining…
Ben LubarIt's December, and that means it's time for the monthly update! There's a message here, addressed to you. M868 Flamer Unit: Adjusted friendly fire damage and duration on normal friendly fire difficulty. (Thanks, ModdedMarionette). Hardcore…
Ben Lubar22A7-Z Prototype Assault Rifle: Removed damage falloff from alternate fire. Now does 1 damage regardless of distance for any target it hits rather than some fraction of a point of damage. IAF Incendiary Sentry Gun: Fixed a 2010 era bug…
Ben LubarMapping Competition 2024 Winner Downed Station by legomanas {STEAM_CLAN_IMAGE}/27357479/96f9509932b257ed89058f3bcb4450083fe834de.png Changes in this update Removed the cl_interp convar. The game will now act as if it was set to 0. Improved…
Ben LubarThis month's update is mainly related to weapon quality of life improvements. X-33 Damage Amplifier: Fixed a carried beacon not reliably connecting to the gun of the marine carrying it. X-33 Damage Amplifier: rd_buff_grenade_attach_sw_auto…
Ben LubarNew material shader: RDCharacter This replaces the VertexLitGeneric shader and the AlienSurfaceFX and NightVisionSelfIllum material proxies for characters in Alien Swarm: Reactive Drop. For Modders If your mod does not contain VMT files for…
Ben LubarCommander, The Office appreciates your hard work on the anomalous materials project. The folks in the lab say they'll be ready for phase 2 soon. We'll let you know when it's ready. You'll know it when you see it. Oh, and happy wrath month.…
Ben LubarWe've extended the deadline for submissions to the 2024 mapping competition until the end of July, so you have two extra months to make your mission. An update has been released with the following changes: Balance Reduced the attack speed…
Ben LubarFixed an issue that caused alien corpses to fade slower than intended.
Patch notesFixed an issue that was causing dedicated servers to crash when a player connected.
Patch notesIt's Alien Swarm: Reactive Drop's 7th birthday, which means it's time for our second annual mapping competition! The theme this year is Space Station. Create a standalone mission (of any type) that takes place on a space station or other…
Ben LubarIt's Alien Swarm: Reactive Drop's 7th birthday, and that means a week of double experience points from missions, our second annual mapping competition, and the possibility of cake. 2023 in Review Since Alien Swarm: Reactive Drop's 6th…
Ben LubarWe've updated the game client with a fix for bug reports written in Chinese only sending the first half of the text.
Patch notesWe've fixed a few issues reported by the community. Fixed a crash on the main menu when hovering over the public lobby list or list of friends. The Season 20 Heroes of the Interstellar Armed Forces medals were given out with the wrong…
Patch notesNext month (April) is Alien Swarm: Reactive Drop's 7th anniversary. We're not planning on having a huge update this year because we've decided it's better to release new content as soon as it's ready instead of waiting for an arbitrary time…
Ben LubarWe've released a hotfix with the following changes: Fixed a crash related to bounty notifications on the main menu. (hotfix went out shortly after midnight UTC on Feburary 1st) Fixed bounty notifications duplicating the first mission in a…
Patch notesThis month's update includes some large changes to Heroes of the Interstellar Armed Forces, as well as some balance changes for the Infection Deathmatch mode and several other fixes. A note on Lag Compensation The internet doesn't transmit…
Ben LubarStarting in Season 20 (February 2024), Heroes of the Interstellar Armed Forces is gaining two new sources of points. Additionally, we are updating the score multipliers of nearly every mission and many challenges. What's Heroes of the…
Ben LubarHappy new year! This month's update contains fixes for controller issues, updates to the Infection deathmatch challenge, and a few miscellaneous fixes and new features. Official Missions BioGen Corporation: Operation X5: Fixed a door that…
Ben LubarSpectators will now see the full length laser pointer for the marine they are spectating. Using the healing ability on a medic weapon now dims the laser pointer in the same way that firing any other gun does. Lobbies with no ping…
Patch notesMenus We're testing the new main menu layout that will be officially launching on April 20, 2024. The main menu has been redesigned, with information about the current Heroes of the Interstellar Armed Forces season, recent major updates…
Ben LubarThis patch addresses some issues in the November 1st update. Reduction: Silent Station: Increased speedrun time limit from 4:40 to 4:50. Reduction: Silent Station: Removed a dialogue trigger with no associated dialogue. Reduction: Operation…
Patch notesThis month's update contains many features requested by the community. New Campaign: Reduction A remastered version of the Reduction campaign is now available in the game. Official Missions Tears for Tarnor: Oasis Colony Spaceport: Fixed…
Ben LubarHere are some fixes for recently-reported bugs and a few map and workshop improvements. IAF HAS42 Devastator: Increased firing sound volume for the player firing the weapon. Fixed end-of-mission stat graph lines being unexpectedly far apart…
Ben LubarFixed the previous user's Workshop addon enabled state being used on the first game launch after switching Steam accounts. Fixed controller icons in hints rendering incorrectly for non-XInput controllers. Reduced volume of some frequently…
Ben LubarMissions Operation Cleansweep: Storage Facility: Removed tech marine requirement. Added a chainsaw near the first door and twin pistols near the last door. Research 7: Illyn Forest: Removed "Melee" game instructor hint from blockade.…
Patch notes2023 Mapping Competition Congratulations to the winner of the 2023 mapping competition: The Gauntlet: Arctic! {STEAM_CLAN_IMAGE}/27357479/e686fb7ba8743375c03bec9e970bb62347b1f35f.png All participants have also received the 2023 Mapping…
Ben LubarWe made changes to how Heroes of the Interstellar Armed Forces servers receive their mission list so it can be modified without requiring a full game update. Added a new command rd_hoiaf_debug to view information about the current ranked…
Ben LubarA hotfix has been released with the following changes: Fixed a crash related to a server becoming empty mid-mission. Made changes to addon loading to hopefully address some servers not showing challenges they should have enabled. Marine…
Patch notesWe're hard at work on next year's major update, but in the meantime there were some issues we wanted to address more urgently. This release fixes some crashes, oddities with weapons, and issues with new maps, and also contains an…
Ben LubarAn update has been released for Alien Swarm: Reactive Drop. Added several community challenge modes to Heroes of the Interstellar Armed Forces. Fixed a bug causing anti-cheat to fail to initialize on the sg-servers and Steampunk ranked…
Patch notesAn update has been released containing the following changes: Accident 32: Confined Facility and J5 Connector: Reduced networking overhead from minecarts. Tilarus-5: Yanaurus Mine: Fixed scripted doors not visually falling. v45 Electric…
Patch notesAn update has been released to address the following issues. Some of these issues were addressed in hotfixes yesterday and today. Firing projectiles causes lag. Marine bots in follow mode cause lag. The Hot Enough achievement is…
Patch notesToday, Alien Swarm: Reactive Drop celebrates 6 years on Steam. You'll earn double experience points all week, but we know what you're really here for. Let's unwrap some presents: New Campaign: Accident 32 Mysterious green glowing gems are…
Ben LubarIt's Alien Swarm: Reactive Drop's 6th birthday on Steam! Later today, there will be a big update with lots of changes and new content, but before we get to that, we're trying something new. This week, any mission you complete will award…
Ben LubarWe're still preparing for the big celebration of Alien Swarm: Reactive Drop's birthday on April 20th, but in the meantime, there are some bugs that need fixes sooner rather than later. There will be more fixes in a few weeks, but for now…
Patch notesToday marks the start of Heroes of the Interstellar Armed Forces season 8, and we're adding more missions and challenges from the Workshop to the list of content you can play on participating servers. Campaigns and Bonus Missions The…
Ben LubarA hotfix to address issues in ranked play has been released. Fixed grub stomping counting as alien kills in places it was not intended to, such as the achievements Smoking Barrels and Damage Amped. Fixed marines getting stuck in fire…
Patch notesHot off the tail of last week's update, here are some fixes for bugs reported by the community. Weapons IAF Medical Gun: Fixed collision being oriented differently than the visible model. CR18 Freeze Grenades: Fixed collision being oriented…
Patch notesToday's update fixes some inconsistencies in various weapons and campaigns. It also adds the ability to assign screen effects to individual marines, and a new trigger to apply different HDR settings to different areas of a map. Campaigns…
Ben LubarAs Season 2 of Heroes of the Interstellar Armed Forces comes to an end, we are changing the competition from quarterly to monthly. We've also got a wide assortment of bugfixes and a few new VScript functions. Campaigns Jacob's Rest: Rydberg…
Ben LubarWhat Steam runs, and with what. Straight from the app configuration.
| Description | Executable | Arguments | Platform | |
|---|---|---|---|---|
| Launch | reactivedrop.exe | -novid | windows |
It runs on public data and somebody's spare time.
https://paypal.me/KintaroPalPay[email protected]0x4d559C765AA8BFe336E36d5b76024926767eD38dTJtctWU9uetJaTBoSybd1RErW7n9duTKVG