Valve’s long-lost prototype Portal prequel appears online after nearly 20 years

As reported by Kotaku, a near-mythical canceled Valve game called F-Stop has been reconstructed from material contained in separate leaks. Direct access to the build seems a little shaky at the moment, but full playthroughs of the game, like this one by Meme Man? on YouTube, are starting to pop up online.

Most of F-Stop’s assets came out in this August’s Steam “teraleak,” but the final pieces⁠—F-Stop’s source code and mapsrc data⁠—were only just acquired by the Valve Cut Content Team Discord, which appears to have gone private amid all the newfound attention over F-Stop. With the Discord currently invite-only, you gotta know a guy (or know a guy who knows a guy) to play it yourself.

The Half-Life Wiki has the skinny on F-Stop’s origins in the “Directed Design Experiments.” Following the megahit launch of the Orange Box in 2007, Gabe Newell effectively shut Valve down for a three-month game jam that produced five prototypes, F-Stop among them.

It applied Team Fortress 2’s cel-shaded art style to a vision of Aperture Science in its prime, all mid-century wood-paneled office optimism. F-Stop’s central mechanic was a camera that could capture objects in the world, then place them elsewhere to solve puzzles. The excellent 2023 game Viewfinder would apply a similar concept to a full commercial release.

But while loved internally at Valve, F-Stop’s playtests were apparently more tepid. The game was shelved, though elements of its worldbuilding would appear in Portal 2 and Aperture Desk Job. It’s fun to recognize some of these early ideas in the F-Stop longplays: From the jump, we get a version of Cave Johnson (sadly sans-J.K. Simmons in prototype) talking to the player, as well as the first instance of Aperture Personality Cores as companions in the puzzling.

Given F-Stop’s “road not taken” nature, particularly compared to the megathit Left 4 Dead and Portal 2 that would follow, I don’t really mourn the fact that we never got to play its final version. It is, however, extremely cool that the prototype game is now preserved for posterity.