XIII (pronounced: Thirteen) is a first-person shooter video game developed by Ubisoft Paris and published by Ubisoft for most platforms except for the OS X version, which was published by Feral Interactive. Loosely based on the 1984 Belgian comic book XIII, the player controls (through a first-person view) the protagonist Jason Fly (XIII), a confused and amnesic man who searches for his identity throughout a comic book-style, cel-shaded world. Found stranded on a beach by a lifeguard, Fly is accused of having killed the President of the United States. The accusation later transpires as mistaken, as Fly finds himself facing a gang of 20 conspirators ("The XX") who aim to overthrow the government. The game was released for Microsoft Windows, PlayStation 2, GameCube, Xbox and OS X.