Leaked files rebuild a playable version of cancelled Portal prequel F-Stop

A playable version of F-Stop, the Portal prequel that Valve cancelled, has been rebuilt from leaked material. Most of its assets came from a 12-terabyte leak in August. The leak did not include the game's source code or map data. Those pieces reached the Valve Cut Content Discord this week, which let a near-complete build be put together.

Some of F-Stop's dialogue and elements later appeared in Portal 2. The game itself, though, departs sharply from the main Portal series. Its core mechanic is a camera. Players capture an object by photographing it and then place that object somewhere else.

How the build came together

The August leak was large, but it lacked the parts needed to run the game. The source code and map data were the missing pieces. Their arrival on the Discord server closed that gap. Leakers combined the two sets of files into a build that can be played.

The result is rough. It is still the closest thing to a release that players are likely to see. Valve has not released F-Stop and has not commented on the rebuild.

Background

F-Stop was a prequel to Portal that never shipped. Its cancellation has long drawn interest from fans of the series. The camera-based puzzle design marks a clear break from the portal-gun gameplay that defines the main titles.

What is not yet known is whether Valve will act against the leaked build, or whether further material will surface. Any playable copy is unofficial and unsupported.