Valve’s Cancelled Portal Prequel F-Stop Has Leaked

F-Stop , Valve’s cancelled 2007 Portal prequel, has leaked online–and yes, it’s fully playable. If you’ve heard of F-Stop , you don’t need me to tell you why this is a huge deal. But if you haven’t, then you’re in for quite the history lesson. In 2007, Valve spent three months on a project that Gabe Newell would later dub the Directed Design Experiments. Now, I’m not going to attempt to tell the story better than the folks at the Half-Life wiki have before, so here’s the short version: during these three months, Valve broke off into five teams.