onic the Hedgehog heads off to Never Lake where the Little Planet appears once a year. There he comes across an admirer, the tarot card-reading Amy Rose, who follows him onto the planet. Unfortunately, Dr. Robotnik has turned the island into his own personal fortress and seeks the Time Stones, which will put the past, present, and future of the Little Planet into his wicked hands. He also has his robot lackey Metal Sonic kidnap Amy. It's up to Sonic to save Little Planet and Amy before it's too late.

Overview from IMDb.com