Portal

Portal was among the most acclaimed surprises of 2007 - a short but exceptionally inventive puzzle game built around the concept of a portal gun made Valve famous far beyond its previous titles, whose reputation up to that point had rested mainly on Half-Life. The player progresses through a series of test chambers under the guidance of the artificial intelligence GLaDOS, with the only tool being a gun capable of opening two linked portals in space - a simple concept from which the game extracted dozens of follow-up puzzles built around momentum and spatial reasoning. The game is also remarkably short to complete, yet it managed to leave a far deeper impression than many much longer titles of the time. On Xbox 360 the game launched on October 10, 2007 as part of The Orange Box compilation, which alongside Portal also included Half-Life 2 with both episodes and Team Fortress 2 - a bundle in which Portal was more of a bonus that ultimately stole most of the attention and became more famous than the rest of the collection.

The Xbox 360 version ran on the same Source engine as the rest of the collection and offered a full set of achievements via Xbox Live, which in 2007 gave many players an extra incentive to finish the game one hundred percent and get through the harder bonus chambers too. In terms of gameplay and content it is identical to the PC release - the same test chambers, the same story about the artificial intelligence GLaDOS, and the same closing song Still Alive, which became a phenomenon in its own right.

The Xbox 360 edition of The Orange Box also launched on exactly the same day as the PC version, so players on both platforms experienced Portal for the first time simultaneously. This differed fundamentally from the PlayStation 3 version, which didn't reach the market until two months later and, on top of that, came with markedly worse technical quality caused by the fact that the port for the Sony console wasn't made directly by Valve but by an external contractor.

Why play it: For Xbox 360 players, Portal launched within The Orange Box on the same day as the PC version, so they got to enjoy it without the delay and technical compromises that plagued the later PlayStation 3 port.