F-Stop, the Portal prequel developed and later canceled by Valve in 2007, has now been restored by the community into a nearly complete playable version using multiple batches of leaked materials. Players report that while the current version still lacks a small amount of assets and dialogue, approximately 99% of the content is available.
F-Stop, the Portal prequel canceled by Valve in 2007, has leaked online—and is currently fully playable. If you've heard of F-Stop, I don't need to say much; you surely know how significant this is. But if you haven't, then let me give you a proper history lesson.
In 2007, Valve spent three months on a project that Gabe Newell later dubbed "Directed Design Experiments." During those three months, Valve split into five groups. Each group designed and partially produced a video game "experiment," with the fifth group named "F-Stop."
F-Stop was originally conceived as a prequel to Portal, with gameplay centered around using Aperture Science's experimental camera to change perspectives and solve puzzles. Gabe Newell himself was fascinated by the project, but test players weren't quite on board. Ultimately, F-Stop was canceled, and some of its dialogue, characters, and mechanics were reworked and incorporated into Portal 2.
Well, there's no need to treat it as scrap anymore, because thanks to the efforts of several leakers and the Valve Cut Content team, F-Stop is now playable (almost) in its entirety.
If you're curious about how this leak happened, here's a detailed explanation: it was actually the culmination of three separate leaks.
Some may recall that in late August, approximately 13 TB of Steam depot data was leaked online. This incident, known as Steam2, appeared to contain nearly all Steam depot data from 2003 to 2013, and most surprisingly, it included assets from F-Stop.
However, although the Steam2 leak contained most of F-Stop's assets, it did not include F-Stop's source code or mapsrc data (the folder name Valve uses for storing map source data). It seems that these last two pieces of the F-Stop puzzle were leaked within the past 48 hours via the Valve Cut Content project's Discord server.
According to server administrators, the person who leaked the F-Stop map source files initially asked for $1,000, but somehow ended up giving them away for free. The Valve Cut Content team has verified the authenticity of the map files, and the community has combined these three parts to finally present a complete, playable version of F-Stop.
Those who have played it report that although the game still seems to be missing some assets and dialogue, the overall completion rate has reached 99%. This isn't surprising, after all, if Valve had really intended to officially release this game, they would have polished it further. But honestly, "99% complete" is much better than the 0% completion we had this time last week.