The second game featuring Sega's mascot Sonic the Hedgehog.  The evil doctor Robotnik wants to conquer the world. In order to do that, he imprisons and transforms all animals into robots. This way they can build his powerful weapon, the Death Egg. Along with your sidekick Tails you must collect all the Chaos Emeralds, free the animals and defeat Robotnik.  The game features 10 big zones in which you must defeat enemies and gather rings. It also features a 2 player mode, in which you can race with a friend.