Portal 2 is a first-person action/puzzle Video Game, developed by Valve Corporation. It is the sequel to the critically acclaimed 2007 Video Game Portal and was announced on March 5, 2010, following a week-long alternate reality game based on new patches to the original game.
Though initially slated for release in the last quarter of 2010,[7][8] the game was postponed to the week of April 18, 2011.[9] The game will be released by Valve, ...