Cốt truyện

After collecting the seven Chaos Emeralds and defeating the Death Egg, Sonic and his new friend, Tails, are attacked by a familiar foe, Metal Sonic! Metal knocks the seven emeralds out of Sonic, striking down Sonic’s Bi-Plane, the Tornado, as the duo crash land on the unfamiliar Starshine Island. Upon arrival, Sonic and Tails notice that their surroundings have been trampled by Badniks, while the nefarious Dr. Robotnik appears to be multiple steps ahead. Robotnik has begun the investigation of the island's mysterious ruins, A temple containing a powerful entity known as the Celestial Star. Rumour has it this star can rival the power of the Chaos Emeralds when fully powered, but it’s a race to see who can power and retrieve the Celestial Star first!