The new story arc centered on a search for a Chaos Emerald thief takes our heroes to the opulent city of Sequin.

On the other hand, the 'dark' campaign saw players controlling Shadow the Hedgehog, Doctor Eggman and Rouge the ... This power is hinted at in the latest teaser for Sonic 3, where he appears ...

and while we know of at least 2 characters that will appear in Sonic the Hedgehog 4, there are plenty more that could be introduced, including favorites like Rouge, Silver, Fang, and Big the Cat.