After defeating Metal Sonic again, Sonic, Tails, Knuckles, and Amy are heading to a new island called the North Star Islands, as they discover Dr. Eggman is once again converting animals into robot and trying to take over the world, this time while even converting giant animals into Super-Badniks as well seeking a mysterious dark force within the islands to assist his latest plot. Along the way, they also cross paths with the returning Metal Sonic, a robotic versions of Sonic’s friends with a doll version of Tails, Team Hooligans, hired by Eggman as bounty hunters, and their meek partner Trip the Sungazer. With all these new threats in their way, it's up to Sonic and his friends with Longclaw along the way to free the animal friends once more, explore the mysterious Northstar Islands alongside its secrets, and stop Eggman's latest plan of world domination.
