Portal

Portal is a single-player puzzle-platformer 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, and for the PlayStation 3 on December 11, 2007. The Windows version of the game is also available for download separately through Valve's content delivery system Steam[2] and was released as a standalone retail product on April 9, 2008. A stand-alone version called Portal: Still Alive was released on the Xbox Live Arcade service on October 22, 2008; this version includes an additional fourteen puzzles. A Mac OS X version was released as part of the Mac-compatible Steam platform on May 12, 2010.
The game consists primarily of a series of puzzles that must be solved by teleporting the player's character and simple objects using the Aperture Science Handheld Portal Device (ASHPD, also dubbed the "portal gun"), a unit that can create inter-spatial portals between flat planes. The player character, Chell, is challenged by an AI named GLaDOS to complete each puzzle in the Aperture Science Computer-Aided Enrichment Center using the portal gun with the promise of receiving cake when all the puzzles are completed.