Choose from a roster of characters from the Sonic the Hedgehog series and fight in a tournament to earn Chaos Emeralds to power a spaceship and stop Doctor Robotnik and Metal Sonic from buil... Read allChoose from a roster of characters from the Sonic the Hedgehog series and fight in a tournament to earn Chaos Emeralds to power a spaceship and stop Doctor Robotnik and Metal Sonic from building a fortress in space.Choose from a roster of characters from the Sonic the Hedgehog series and fight in a tournament to earn Chaos Emeralds to power a spaceship and stop Doctor Robotnik and Metal Sonic from building a fortress in space.