Sonic, Knuckles, and Tails reunite against a powerful new adversary, Shadow, a mysterious villain with powers unlike anything they have faced before. With their abilities outmatched in every way, Team Sonic must seek out an unlikely alliance in hopes of stopping Shadow and protecting the planet.

Mumble the penguin has a problem: his son Erik, who is reluctant to dance, encounters the Mighty Sven — a penguin who can fly! Things get worse for Mumble when the world is shaken by powerful forces, causing him to bring together the penguin nations and their allies to set things right.