The Xbox 360 title beat previous records set by blockbuster theatrical releases like “Spider-man 3” and novels such as “Harry Potter and the Deathly Hallows.”

“Halo 3” is the conclusion to the epic trilogy and picks up where “Halo 2” left off, answering questions around the fates of the beloved protagonist Master Chief and his artificial intelligence sidekick Cortana as they struggle to save humankind from destruction at the hands of the alien coalition known as the Covenant. In addition to the rich storyline, “Halo 3” continues the franchise’s grand tradition of delivering innovative online multiplayer experiences via Xbox LIVE, the world’s largest social network on TV.

“Halo 3 has become a pop-culture phenomenon,” said Shane Kim, corporate vice president of Microsoft Game Studios. “Not only is “Halo 3” setting sales records, it’s also redefining entertainment.

Within the first 20 hours alone, we’ve seen more than a million Xbox LIVE members come online to play Halo 3 – that makes September 25 the most active Xbox LIVE gaming day in history.”

Retailers have also expressed their excitement about the launch of “Halo 3.”

Bob McKenzie, Senior Vice President of Merchandising for GameStop Corp commented that, “With consumer demand for Halo 3 and related products, we expect it to be the biggest video game title generator in GameStop's history."

“The initial demand we’ve seen for ‘Halo 3’ has been astounding, and the game is on track to become the number one gaming title of all time. ‘Halo 3’ is a genuine entertainment phenomenon and our customers have responded very enthusiastically to the release,” said Jill Hamburger, vice president of movies and games at Best Buy.