"This is a huge milestone for us and a big cause for celebration at Bungie and Microsoft Game Studios," said studio head Harold Ryan. "This is the game we've always wanted to make and certainly the best game our studio has developed. We can't wait for gamers to get their hands on it on Sept. 25."

Microsoft, always bullish on Halo franchise sales projections, expects the game to "shatter day-one entertainment sales records," as the game has already achieved one million retail preorders in North America. The release of Halo 2 for Xbox saw first-day sales that eclipsed both film and game industry records.