Content overview: “Canceled Portal Prequel F-Stop Now Playable After Massive Valve Leak”. A fully playable version of Valve's canceled Portal prequel, F-Stop, has been assembled by the community, thanks to the massive 12-terabyte leak that surfaced in August. While the initial leak lacked source code and map data, those missing elements were recently shared on the Valve Cut Content Disco While the initial leak lacked source code and map data, those missing elements were recently shared on the Valve Cut Content Discord, enabling fans to piece together a nearly complete game.
F-Stop was originally conceived as a Portal prequel featuring a new gameplay mechanic instead of portals, but it was ultimately shelved during development. This leak offers a rare look at an unreleased Valve project, giving players insight into the company's creative process and what might have been. This listing links straight to the original page, where the content is available in full.