The world embraces 'green' energy to help the environment, and Sonic's adopted city, Station Square, is no different. But some choose to use eco-friendly means toward eco-unfriendly ends! Namely the evil Dr. Eggman, who uses his new 'bots powered by the sun, wind and water to devastate the city and leave Sonic and friends on the defensive! Now Eggman is free to pursue the biggest natural energies ever, the Chaos Emeralds and the Master Emerald. With these power sources in hand, Eggman will be in control of more power than the world has ever seen. Will Sonic be literally powerless to stop Eggman this time?