Rivals, fakers, and doppelgngers have been scourges to Sonic for years, but Dr. Starline's newest creations pose an entirely new threat. New challengers Surge and Kit were designed for a single purpose: to replace Sonic and Tails as the world's greatest heroes! And that means it's not just the Blue Blur and his friends who should be wary-Dr. Eggman better watch out too! But has Dr. Starline gone too far this time?