Portal is a 2007 first-person puzzle-platform video game developed by Valve Corporation . The game was released in a bundle package called The Orange Box for Microsoft Windows and Xbox 360 on October 9, 2007 [ 5 ] [ 6 ] and for the PlayStation 3 on December 11, 2007. [ 7 ] The Windows version of the game is available for download separately through Valve's content delivery system Steam [ 1 ] and was released as a standalone retail product on April 9, 2008. [ 4 ] A standalone version called Portal: Still Alive was released on the Xbox Live Arcade service on October 22, 2008; this version includes an additional 14 puzzles.