Priced £23.99 on PS4, Xbox One, PC, PS3 and Xbox 360.
Rose to fame as producer on the first Assassin's Creed game.
Oddworld Inhabitants is working to overcome platform challenges.
Wasn't practical to offer the game on two Blu-ray discs, says Halo franchise development director Frank O'Connor.
Perhaps we'll find out about the leaked single-player modes.
Borderlands: The Pre-Sequel takes third, with F1 2014 new at No.10.