Sonic the Hedgehog protagonist Sonic the Hedgehog, a blue hedgehog able to run at supersonic speeds, and recurring villain Dr. Eggman, an evil scientist whose ambition is to conquer the world. Among Sonic's many allies, the most well-known include: Miles "Tails" Prower, a twin-tailed, highly intelligent yellow fox who is Sonic's sidekick and best friend; Amy Rose, a pink hedgehog who is Sonic's self-proclaimed girlfriend and a hero in her own right; Knuckles the Echidna, a coolheaded red echidna who is the guardian of the Master Emerald; Shadow the Hedgehog, an anti-heroic doppelgänger of Sonic with a dark past; and Metal Sonic, a
Sonic the Hedgehog 2 Sonic the Hedgehog 2 Development of the game began in November 1991. The game was developed by both Japanese and American staff at Sega Technical Institute; art director Tim Skelly designed the appearance of the game's new 3D special stages, which were based on an earlier tech demo created by Yuji Naka. The staff increased the speed of "Sonic the Hedgehog 2" in comparison to its predecessor. As with the first installment, the soundtrack was composed by Masato Nakamura. "Sonic the Hedgehog 2" sold over six million copies, making it the second-best-selling Genesis game behind the original "Sonic the Hedgehog".