Halo 2 is a 2004 first-person shooter video game developed by Bungie. Released for the Xbox video game console on November 9, 2004, the game is the second installment in the Halo franchise and the sequel to 2001's critically acclaimed Halo: Combat Evolved. A Microsoft Windows version of the game was released on May 31, 2007, developed by an internal team at Microsoft Game Studios known as Hired Gun. The game features a new game engine, as well as using the Havok physics engine; added weapons and vehicles, and new multiplayer maps. The player alternately assumes the roles of the human Master Chief and the alien Arbiter in a 26th-century conflict between the human United Nations Space Command, the genocidal Covenant, and the parasitic Flood.