The game was released in Australia, Europe, and North America in September 2008, and then in Japan the following year. Sonic Chronicles initially focuses on the events surrounding the kidnapping of Knuckles and the disappearance of the Chaos Emeralds after the defeat of Doctor Eggman, before moving on to follow the cast of characters across two dimensions as they encounter a new ally, Shade the Echidna, and seek to stop the invasion of their world by Ix, the leader of Shade's tribe, the Nocturnus. The game was BioWare's first handheld video game project, and is a part of the Sonic the Hedgehog series. Sonic Chronicles: The Dark Brotherhood, or simply Sonic Chronicles, is a role-playing video game developed by BioWare and published by Sega for the Nintendo DS.