Valve’s long-lost Portal prequel game has surfaced online nearly 20 years later

According to Kotaku, an almost mythical canceled Valve game called F-Stop has been reconstructed from material contained in separate leaks. Direct access to the build is a little shaky at the moment, but full playthroughs of the game, like this one from Meme Man? on YouTube, are increasingly appearing online.

Most of F-Stop’s assets come from August’s so-called “teraleak” on Steam, but the final pieces—F-Stop’s source code and mapsrc data—were recently acquired by the Valve Cut Content Team Discord, which appears to have gone private given the increased attention surrounding F-Stop. Since the Discord is currently invite-only, you’ll need to know someone (or know someone who knows someone) who can play the game themselves.

The Half-Life Wiki provides the details of F-Stop’s origins in the “Directed Design Experiments” section. After the success of the mega-hit Orange Box in 2007, Gabe Newell put Valve into a game jam phase for three months that produced five prototypes, including F-Stop.

It transposed the cel-shaded art style of Team Fortress 2 onto a vision of Aperture Science in its heyday, thoroughly optimistic in the style of mid-20th century wood-clad offices. The central mechanic of F-Stop was a camera that could capture objects in the world and then place them elsewhere to solve puzzles. The excellent 2023 game Viewfinder would take on a similar concept in a full commercial release.

But while F-Stop was very popular internally at Valve, the playtests were apparently much more subdued. The game was shelved, although elements of its world-building later appeared in Portal 2 and Aperture Desk Job. It’s fun to recognize some of these early ideas in the F-Stop long plays: right from the start we hear a version of Cave Johnson (unfortunately without J.K. Simmons in the prototype) talking to the player, as well as the first variant of the Aperture personality cores as a companion when solving the puzzles.

Given the “road not taken” of F-Stop, especially compared to the megahits Left 4 Dead and Portal 2 that would follow, I really don’t mourn the fact that we never got to play the finished version. However, it is extremely cool that the prototype game is now being preserved for posterity.