Halo 3 is a 2007 first-person shooter video game developed by Bungie for the Xbox 360 console. The third installment in the Halo franchise following Halo: Combat Evolved (2001) and Halo 2 (2004), the game's story centers on the interstellar war between 26th-century humanity, a collection of alien races known as the Covenant, and the alien parasite known as the Flood. The player assumes the role of the Master Chief, a cybernetically enhanced supersoldier, as he battles the Covenant and the Flood. In cooperative play, other human players assume the role of allied alien soldiers. The game features vehicles, weapons, and gameplay elements familiar and new to the series, as well as the addition of saved gameplay films, file sharing, and the Forge map editor—a utility which allows the player to perform modifications to multiplayer levels. Halo 2 had originally been intended to wrap up the story begun with Combat Evolved, but development difficulties led to a cliffhanger ending. Bungie began developing Halo 3 shortly after Halo 2 shipped. The game was officially announced at E3 2006, and its release was preceded by a multiplayer beta open to select players who purchased the Xbox 360 game Crackdown. Microsoft spent $40 million on marketing the game, in an effort to sell more game consoles and broaden the appeal of the game beyond the established Halo fanbase. Marketing included cross-promotions and an alternate reality game. Halo 3 was released on September 25 and grossed US$170 million on its first day of release, rising to $300 million in its first week. The game sold in excess of 14.5 million copies and was the best-selling video game of 2007 in the United States. More than one million people played Halo 3 on Xbox Live in the first twenty hours. Overall, the game was well received by critics, with the Forge and multiplayer offerings singled out as strong features; however, some reviewers criticized single-player aspects, especially the plot and campaign layout. Halo 3 is frequently listed as one of the greatest video games of all time. A sequel, Halo 4, released in November 2012, was developed by 343 Industries. Halo 3 was re-released as part of Halo: The Master Chief Collection for the Xbox One in November 2014 and for Microsoft Windows on July 14, 2020.