A fully playable version of Portal prequel F-Stop leaked

A playable version of the canceled Portal prequel F-Stop has been reconstructed from a 12-terabyte leak and additional source code and map data that were recently released. The game is a camera-based puzzle game where players capture items by taking their picture and relocate them using Polaroid-like photos. F-Stop was developed as part of Valve's 'Directed Design Experiments' in 2007, which was a three-month period where Valve split into five teams to build new game experiments. The game is relatively short, with its full campaign clocking in at under an hour.