What remains of canned Portal prequel white whale F-Stop is now fully playable thanks to modders and some big leaks

If you're something of a Portal or Half-Life head, you'll probably already be familiar with F-Stop, an unreleased Portal prequel that remained quite mysterious for many years. Back in 2020, a much deeper look was revealed in a semi-official capacity, revealing a pretty neat concept (that isn't so dissimilar to that of Superliminal). Now, all these years later, assets and source code for the game has leaked, and what exists of F-Stop is fully playable.

As spotted by Kotaku, the Valve Cut Content team and a number of leakers have been able to put together a playable version of F-Stop so that you can try it out for yourself. Mechanically, it works like so: you take a picture of an object, and said object disappears, turning it into a photo. You can then use this photo to rematerialise the object, sometimes changing the scale of it to help you navigate particular puzzles. It's cool! Just not something Valve thought was worth going all in on, evidently.

So the story goes, Valve overlord Gabe Newell did actually quite like the early version of the game that never was, it's just it didn't test all that well. I do kind of think that this is a lesson in not always listening to test audiences; the aforementioned Superliminal really is quite similar in execution, even tonally it's on the same kind of wavelength, and it ended up being quite a tight little experience that ended up being received quite positively, generally. In the end, bits of F-Stop were Frankensteined into Portal 2, so, at least we got that out of it!

The reason for the delay in being able to play F-Stop in this unofficial capacity is because of the crucial source code and map data. Back in August about 12TB of Steam data leaked, but that only contained the assets for F-Stop. Mods in the Valve Cut Content Discord server said that the person who leaked the F-Stop mapsrc asked for $1000 before just handing over the data in any case. Glad they did, $1000 bucks is a lot, I wouldn't pay it myself. Cool little bit of history to be found here, shame it never materialised in the way it was meant to.