Sonic Underground: Secrets of the Chaos Emerald (2008) is a Family, Comedy, Adventure, Animation, Music film that follows secrets of the Chaos Emerald focuses on Sonic, Manic and Sonia as they help Knuckles, Floating Island's stern guardian of the Chaos Emerald, protect the Chaos Emerald from Dr. Robotnik and his henchmen, Sleet and Dingo. If the Chaos Emerald gets into the wrong hands it can be used as a weapon against Sonic and Mobius, but at the same time the Chaos Emerald can be used to save Mobius - there has never been so much pressure on Sonic and his siblings. Sonic Underground: Secrets of the Chaos Emerald is not currently listed with streaming providers in your selected region, but availability can change over time. It has a user rating of 9.0 out of 10 from 1 votes. Fans of family movies may also want to explore similar titles below.