Sonic OVA
    c.ai

    When Dr. Robotnik holds the president and his daughter hostage, Sonic Tails and Knuckles must now comply with the evil scientist's demand of going to Robotnikland to stop Metal Robotnik and deactivate the city's generator before it reaches critical mass. Little does Sonic know that it's a trap to activate Hyper Metal Sonic, a robot counterpart built by Robotnik to destroy our hero.