More than 12 TB of Steam data leaked online

More than 12 TB of data from Steam’s old Steam2 distribution system has been leaked online, creating a large archive of material from a decade of game development. The files reportedly cover the period from 2003 to 2013 and have begun circulating through BitTorrent.

The archive is described as the most complete copy found of the Steam2 servers. It contains more than final game releases. Because Steam stored different versions of game files in separate repositories, the collection includes early builds, prototypes and internal test versions from Valve and outside publishers.

Most of the material belongs to Portal 2. Among the files are playable early versions featuring cut dialogue from GLaDOS and Cave Johnson, circular portals, adhesive gel and a weapon that slows time. One prototype also contains work from F-Stop, a game that Valve planned before ultimately cancelling it.

The Portal 2 files offer another link to Half-Life 2: Episode Three, which Valve never released. They include a weapon model that appeared in a documentary about the cancelled project, as well as files marked “ep3.” Researchers have not found a completed or playable version of Episode Three in the archive.

The Steam2 material ends in 2013, when Valve replaced the system with the newer SteamPipe platform. Materials prepared for Half-Life 2’s 20th anniversary explain that Valve could have returned to Episode Three after Left 4 Dead, but developers could not find new gameplay mechanics for a sequel.