Combat Evolved

Halo: Combat Evolved is a 2001 first-person shooter game developed by Bungie and published by Microsoft Game Studios. The game was released on November 15, 2001 for the Xbox, with ports to Microsoft Windows and Mac OS X released in 2003. It is the first installment in the Halo franchise. Set in the 26th century, players assume the role of Master Chief, a cybernetically enhanced supersoldier. Accompanied by an artificial intelligence construct named Cortana and the human forces of the United Nations Space Command, players battle against an alien theocracy known as the Covenant while they attempt to uncover the secrets of the eponymous Halo, a ring-shaped artificial world.