Sonic, Tails, and Knuckles aim to stop a scheme that would turn their sky realm into an underworld, plunging into the planet's core and the ruined Robotropolis city to confront Dr. Robotnik,... Read allSonic, Tails, and Knuckles aim to stop a scheme that would turn their sky realm into an underworld, plunging into the planet's core and the ruined Robotropolis city to confront Dr. Robotnik, unsure if he's ally or foe.Sonic, Tails, and Knuckles aim to stop a scheme that would turn their sky realm into an underworld, plunging into the planet's core and the ruined Robotropolis city to confront Dr. Robotnik, unsure if he's ally or foe.