# Portal Revolution
**Portal: Revolution** is a free, community-made total-conversion campaign mod for Valve's 2011 puzzle game [Portal 2](https://www.edgepedia.org/portal-2), developed and published by Second Face Software and released on [Steam](https://www.edgepedia.org/steam-service) on January 6, 2024.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) It is not an official Valve product, though its lead developer obtained a license to the Portal 2 and [Counter-Strike: Global Offensive](https://www.edgepedia.org/counter-strike-global-offensive) source code directly from Valve, and Valve reviewed the game before allowing its Steam release.[2](https://www.castingcall.club/projects/portal-revolution) • [3](https://www.pcgamesn.com/portal-2/revolution-steam-release) The campaign is a prequel set between Portal and Portal 2, offering more than 40 new test chambers and roughly five to eight hours of play.[1](https://store.steampowered.com/app/601360/Portal_Revolution/)
| Key fact | Detail |
|---|---|
| What it is | Free, community-made total-conversion mod for Portal 2 by Second Face Software, released on Steam January 6, 2024[1](https://store.steampowered.com/app/601360/Portal_Revolution/) |
| Story placement | Prequel set between Portal and Portal 2; the player is awoken by a personality sphere called Stirling[1](https://store.steampowered.com/app/601360/Portal_Revolution/) |
| Content | Over 40 new test chambers across eight chapters; about 5 to 8 hours of playtime[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [4](https://www.thegamer.com/portal-revolution-mod-how-long-to-beat-guide/) |
| New elements | Resurrected Pneumatic Diversity Vent, a new laser cube variant, a Gel Cleansing Field, and over 15 puzzles using only the blue portal gun[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [5](https://www.gamesradar.com/portal-2s-game-sized-prequel-mod-squeezes-in-40-new-puzzles-fully-voiced-original-characters-and-an-8-hour-story/) |
| Engine | Modified Portal 2: Community Edition engine, a custom branch of the CS:GO Source engine built on licensed Valve source code, with real-time volumetric lighting[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [6](https://overkill-media.ghost.io/portal-revolution-interview/) |
| Reception | "Overwhelmingly Positive" on Steam; 96% of 17,712 reviews positive at the store snapshot, 94.16% of about 30,000 reviews per SteamDB; all-time peak of 7,483 concurrent players[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [7](https://steamdb.info/app/601360/charts/) |
| Requirements | Ownership of Portal 2 on Steam (installation not required); Windows 10/11, 8 GB RAM, 13 GB storage[8](https://www.portalrevolution.com/blog/trailer-announcement) • [1](https://store.steampowered.com/app/601360/Portal_Revolution/) |
## Setting and story
The campaign takes place in the interval between the two Valve games, in a decaying Aperture Science facility. The player is a test subject awoken by a personality sphere called Stirling, who enlists them in a mission to find a powerful device capable of restoring Aperture to its former glory.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) The mod features fully voiced original characters alongside the familiar setting.[5](https://www.gamesradar.com/portal-2s-game-sized-prequel-mod-squeezes-in-40-new-puzzles-fully-voiced-original-characters-and-an-8-hour-story/)
A post-credits scene ties the story to [Portal](https://www.edgepedia.org/portal-series) 2's lore by establishing that Aperture Science has a moonbase, connecting to the climactic [Wheatley](https://www.edgepedia.org/wheatley-portal) battle of the later game.[9](https://gamerant.com/portal-revolution-prequel-3-stories-mel-new-game-good-why/) Voice casting continued late in development: in 2023, after one of the main characters' voice actresses departed, the team cast Sarah Jacklin as her replacement.[10](https://www.moddb.com/mods/portal-revolution-spyce-software/news/development-status-15062023)
## Gameplay and puzzle design
The campaign contains 40 brand new puzzles built around new test elements.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) Three stand out. The *Pneumatic Diversity Vent*, a Portal 2 element that did not ship in the final game, is resurrected here.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) A new laser cube variant and a Gel Cleansing Field, described by GamesRadar as rain that cleanses gel, extend the portal-and-gel toolkit.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [5](https://www.gamesradar.com/portal-2s-game-sized-prequel-mod-squeezes-in-40-new-puzzles-fully-voiced-original-characters-and-an-8-hour-story/) More than 15 puzzles use only the blue portal gun, restricting the player to one-way portals.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [5](https://www.gamesradar.com/portal-2s-game-sized-prequel-mod-squeezes-in-40-new-puzzles-fully-voiced-original-characters-and-an-8-hour-story/)
The game is divided into eight chapters, each containing between two and nine episodes.[4](https://www.thegamer.com/portal-revolution-mod-how-long-to-beat-guide/) The developers state that puzzle difficulty starts where Portal 2 stops, with very few chambers requiring mid-air portal firing, and estimate 5 to 8 hours of playtime; HowLongToBeat puts a clear playthrough at around six hours.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [4](https://www.thegamer.com/portal-revolution-mod-how-long-to-beat-guide/)
## Development
Lead developer Stefan Heinz, a game designer and programmer from Austria, began the project in some form as far back as 2016.[6](https://overkill-media.ghost.io/portal-revolution-interview/) • [2](https://www.castingcall.club/projects/portal-revolution) The current iteration started in 2019 and took shape in 2020, when Heinz and his team obtained the source code for Portal 2 from Valve.[6](https://overkill-media.ghost.io/portal-revolution-interview/) Heinz described himself as a [Source](https://www.edgepedia.org/source-game-engine) engine licensee who reached out directly to Valve Software for a license to the Portal 2 and CS:GO source code, and called the mod a passion project that would remain free to play unless Valve allowed it to be sold.[2](https://www.castingcall.club/projects/portal-revolution)
The team ebbed and flowed over the years but settled on a core of seven people, including voice actors, music producers, 3D modellers, and programmers.[6](https://overkill-media.ghost.io/portal-revolution-interview/) By June 2023, after seven years of development, the mod was fully playable start to finish, with all 42 maps gameplay-ready and an estimated 80 to 90 percent complete.[10](https://www.moddb.com/mods/portal-revolution-spyce-software/news/development-status-15062023)
The mod runs on a modified version of Portal 2: Community Edition's engine, itself a custom version of the Counter-Strike: Global Offensive Source engine branch built with licensed Valve source code; press coverage describes the underlying technology as Strata Source, a community derivative of that branch.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [11](https://automaton-media.com/articles/newsjp/20240112-278767/) Team member Rory Lambert, who joined in 2020 as a 3D artist and moved to graphics and engine programming in 2022, implemented real-time raymarched volumetric lighting using C++, DirectX, and HLSL shaders after years of engine work.[6](https://overkill-media.ghost.io/portal-revolution-interview/) • [12](https://rory-lambert.com/portal-revolution/)
The release was announced for January 5, 2024, but shipped a day later, on January 6, 2024 at 17:00 UTC, after a slight delay while Valve reviewed the game; GamesRadar reported in the holiday period that the game was done and could ship at any moment but that Valve had yet to review and accept it.[8](https://www.portalrevolution.com/blog/trailer-announcement) • [3](https://www.pcgamesn.com/portal-2/revolution-steam-release) • [5](https://www.gamesradar.com/portal-2s-game-sized-prequel-mod-squeezes-in-40-new-puzzles-fully-voiced-original-characters-and-an-8-hour-story/) The team had announced no plans for Steam Workshop integration, though custom maps can be made with the SDK and the engine can serve as a base for other mods.[8](https://www.portalrevolution.com/blog/trailer-announcement)
## By the numbers
The Steam figures give a sense of the mod's reach. At the store snapshot it held 96% of 17,712 user reviews positive; SteamDB's later tally across about 30,000 reviews records 29,522 positive (96.2%) and 1,161 negative (3.8%), a 94.16% rating.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [7](https://steamdb.info/app/601360/charts/) The all-time peak of 7,483 concurrent players came on January 7, 2024, the day after release.[7](https://steamdb.info/app/601360/charts/) Within less than a day of launch the mod had over 900 reviews and over 5,000 concurrent players.[3](https://www.pcgamesn.com/portal-2/revolution-steam-release) Later, the developers reported that 1,000,000 individual people had downloaded and launched the game, while it had been added to 2,500,000 Steam accounts.[13](https://steamcommunity.com/app/601360/announcements/?l=english) Owner estimates from third-party trackers range from about 919,900 (VG Insights) to 2.66 million (PlayTracker).[7](https://steamdb.info/app/601360/charts/)
## How it compares with other Portal mods
Portal 2 has supported a substantial modding scene since its 2011 release, and the main series has had no new entry since then.[11](https://automaton-media.com/articles/newsjp/20240112-278767/) Portal: Revolution is not the first Portal prequel mod: Portal Stories: Mel (2015), a standalone mod by Prism Game Studios with a fully voiced story, 22 levels, and about 6 hours of playtime, also explores Aperture's history and served as an inspiration for Revolution.[6](https://overkill-media.ghost.io/portal-revolution-interview/) • [14](https://gamerant.com/portal-2-best-mods/) • [9](https://gamerant.com/portal-revolution-prequel-3-stories-mel-new-game-good-why/)
The other major mods take different mechanical directions. Portal Reloaded adds a third, green portal that lets the player travel in time to a future version of the current area, across 25 new puzzles later expanded with 20 co-op puzzles.[14](https://gamerant.com/portal-2-best-mods/) Thinking with Time Machine gives the player a Time Machine-created clone of themselves to work alongside the portal gun.[14](https://gamerant.com/portal-2-best-mods/) Revolution's approach is closer to Mel's: a long, fully voiced narrative campaign that extends the existing Portal 2 toolkit rather than replacing it, at a scale (40+ chambers, 5 to 8 hours) larger than either Mel or Portal Reloaded's base campaigns.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [14](https://gamerant.com/portal-2-best-mods/)
## Reception and legacy
Steam rated the mod "Overwhelmingly Positive" from launch onward, and press coverage emphasized its polish: Eurogamer noted that most reviews praised how carefully made it was.[1](https://store.steampowered.com/app/601360/Portal_Revolution/) • [15](https://www.eurogamer.es/el-mod-portal-revolution-quiere-convertirse-en-el-portal-3-que-nunca-fue) Destructoid framed the mod as one that is keeping the Portal universe alive in the absence of a new mainline entry.[16](https://www.destructoid.com/portal-revolution-is-a-mod-thats-keeping-the-portal-universe-alive/) GameRant observed that Valve has a history of embracing fan-made content, providing its Source and [Source 2](https://www.edgepedia.org/source-2) engines, tools, and mod kits, and turning mods into commercial releases such as Counter-Strike: Global Offensive, The Stanley Parable, and Black Mesa.[9](https://gamerant.com/portal-revolution-prequel-3-stories-mel-new-game-good-why/)
## Post-release developments
The team followed the release with the features announced before launch: a standalone soundtrack, authoring tools, and developer commentary.[6](https://overkill-media.ghost.io/portal-revolution-interview/) Update 1.6.0 in April 2024 added Japanese and [Brazilian Portuguese](https://www.edgepedia.org/brazilian-portuguese) localization along with map and engine changes.[17](https://doope.jp/2024/04144663.html) In January 2025, an Anniversary Update added in-game developer commentary to mark the first anniversary.[18](https://store.steampowered.com/news/app/601360/view/509568716255527453?l=english) In August 2025 the team removed the native Linux build in favor of running the game through [Proton](https://www.edgepedia.org/proton-software), citing frequent hangs and stutters related to gel rendering in the native build; because Valve had rated the game Steam Deck Verified with the native version, the change required re-review.[13](https://steamcommunity.com/app/601360/announcements/?l=english) • [19](https://www.gamingonlinux.com/2025/08/portal-revolution-drops-native-linux-support-to-focus-on-proton/)
A sequel, Portal: Revolution 2, has been announced as a full singleplayer continuation picking up after the first game, with the player as the same test subject stranded on the moon with Emilia Conly.[20](https://www.portalrevolution.com/blog/announcing-portal-revolution-2) As of the announcement, 16 map blockouts existed and about 15 puzzles had been designed, with two completely new mechanics prototyped; the team is still using Strata Source and stated it aims to keep development within about three years, explicitly not promising it.[20](https://www.portalrevolution.com/blog/announcing-portal-revolution-2) Lambert confirmed on his portfolio that he is working on the sequel in its early stages.[12](https://rory-lambert.com/portal-revolution/)
## References
1. [Portal: Revolution on Steam, Valve/Second Face Software store page](https://store.steampowered.com/app/601360/Portal_Revolution/)
2. [Portal: Revolution project page, Casting Call Club](https://www.castingcall.club/projects/portal-revolution)
3. [Massive Portal mod eight years in the making already flying on Steam, PCGamesN](https://www.pcgamesn.com/portal-2/revolution-steam-release)
4. [How Many Chapters Are There In Portal: Revolution?, TheGamer](https://www.thegamer.com/portal-revolution-mod-how-long-to-beat-guide/)
5. [Portal 2's game-sized prequel mod squeezes in 40 new puzzles, fully-voiced original characters, and an 8-hour story, GamesRadar+](https://www.gamesradar.com/portal-2s-game-sized-prequel-mod-squeezes-in-40-new-puzzles-fully-voiced-original-characters-and-an-8-hour-story/)
6. [The story behind Portal: Revolution — A fan-made prequel to Portal 2, Overkill Media interview](https://overkill-media.ghost.io/portal-revolution-interview/)
7. [Portal: Revolution Steam Charts, SteamDB](https://steamdb.info/app/601360/charts/)
8. [Trailer Announcement, Portal: Revolution official site](https://www.portalrevolution.com/blog/trailer-announcement)
9. [Portal Revolution Makes A Case For An Official Prequel Game, GameRant](https://gamerant.com/portal-revolution-prequel-3-stories-mel-new-game-good-why/)
10. [Development Status 15.06.2023, ModDB](https://www.moddb.com/mods/portal-revolution-spyce-software/news/development-status-15062023)
11. [『Portal 2』ファンメイドMod「Portal: Revolution」無料配信され大盛況, AUTOMATON](https://automaton-media.com/articles/newsjp/20240112-278767/)
12. [Portal: Revolution, Rory Lambert portfolio](https://rory-lambert.com/portal-revolution/)
13. [Portal: Revolution announcements, Steam Community](https://steamcommunity.com/app/601360/announcements/?l=english)
14. [Best Portal 2 Mods, GameRant](https://gamerant.com/portal-2-best-mods/)
15. [El mod Portal: Revolution quiere convertirse en el Portal 3 que nunca fue, Eurogamer España](https://www.eurogamer.es/el-mod-portal-revolution-quiere-convertirse-en-el-portal-3-que-nunca-fue)
16. [Portal: Revolution is a mod that's keeping the Portal universe alive, Destructoid](https://www.destructoid.com/portal-revolution-is-a-mod-thats-keeping-the-portal-universe-alive/)
17. [「Portal: Revolution」日本語対応アップデート配信開始, doope.jp](https://doope.jp/2024/04144663.html)
18. [Portal: Revolution turns 1! - Anniversary Update + In-game Developer Commentary, Steam News](https://store.steampowered.com/news/app/601360/view/509568716255527453?l=english)
19. [Portal: Revolution drops Native Linux support to focus on Proton, GamingOnLinux](https://www.gamingonlinux.com/2025/08/portal-revolution-drops-native-linux-support-to-focus-on-proton/)
20. [Announcing Portal: Revolution 2, Portal: Revolution official site](https://www.portalrevolution.com/blog/announcing-portal-revolution-2)
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*Topic: Encyclopedia › Sports, games, and recreation › Video games and digital play › Games and gameplay › Individual game titles › Individual PC and computer-platform game titles › Platformer and puzzle titles*
*Initially written Sep 17, 2026 · Reviewed: Oct 21, 2026 · Edited: Oct 15, 2026; Oct 21, 2026 · Last review: Oct 21, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license