Sonic the Hedgehog: The Movie

Dr. Eggman (Robotnik in the US version) takes the president and his daughter hostage, forcing Sonic to comply with his demands. Sonic is sent to Eggmanland, where he's supposed to stop Black Eggman and deactivate the city's generator, which is nearing critical mass. However, this turns out to be a ruse to activate Hyper Metal Sonic, a robot designed by Eggman to defeat Sonic.