Sega's blue-haired mascot comes to the Game Gear with seven new zones full of high-speed, robot-busting action in Sonic the Hedgehog 2. After dispatching the maniacal Dr. Eggman in his first adventure, Sonic heads off on a vacation, only to return home and find all of his animals friends missing. Upon finding a note left behind by his vulpine sidekick Miles "Tails" Prower, Sonic bolts into action, jumping, spinning, and bouncing through 21 different acts in an attempt to track down six Chaos Emeralds and save his two-tailed pal. Sonic's traditional fast-paced antics are enhanced by a number of new methods of conveyance, including soaring through the air in a hang glider, speeding over train tracks in a mine cart, skimming along the surface of water, and bobbing underwater in a large bubble. Sonic squares off against a different robotic boss at the end of each act, with the final level pitting the heroic hedgehog against his nemesis, Dr. Ivo Robotnik.