Dr.Ivo Robotnik (his nick name is Eggman) has invaded the peacefull planet of Mobius! , with his army of robots bent on enslaving all the small animals into being living batterys for his army so that he can turn Mobius into on huge city!.Using a combination of the planets animals , gold power rings , and 7 mythical Chaos Emeralds the Dr hopes to have total control of the planet , thats where you come in...Take control of Sonic The Hedgehog , the fastest animal alive! using the Rings and Emeralds free the animals and stop Dr.Robotnik!