The supersonic hero Sonic the Hedgehog arrives on his new plane, the Tornado, on West Side Island, where he meets his new friend Miles “Tails” Prower, a little fox who is interested in the plane. Despite his shyness, Tails loves to fix and build machines, so he is immediately interested in the Tornado. Thanks to that, Sonic and Tails begin a friendship on this basis. Soon, the evil Dr. Robotnik arrives on West Side Island and kidnaps the animals, putting them in robots to find the Chaos Emeralds and build his ultimate weapon – the space station Death Egg. Sonic, this time with the help of Tails, once again faces the villain in battle.
The fifth location the heroes visit is Hill Top Zone, where they climb to the very top of the local mountains and make their way through dark, lava-filled caves. Here the heroes once again face off against Robotnik in his next enhanced modification of Egg Mobile, the Egg Scorcher Mk II.
With time, Sonic manages to find all seven Chaos Emeralds and takes the Super Sonic form. In the end, thanks to the help of Tails and the Tornado modification that the little fox manages to make, Sonic gets on Robotnik’s unfinished Death Egg station, where the hero fights the doctor’s new robot Mecha Sonic as well as Death Egg Bot. After defeating Robotnik and escaping from the Death Egg, Sonic returns to Tails and his animal friends using his Super Sonic form.