Sonic the Hedgehog different media including animation, comic books, and a Hollywood film. The first "Sonic" game, "Sonic the Hedgehog", is a platform game released in 1991. Players control the anthropomorphic blue hedgehog Sonic, who can run and jump at high speeds using springs, ramps, and loops. Sonic must stop Dr. Robotnik from taking over the world using the Chaos Emeralds. "Sonic the Hedgehog 2" (1992) increased the overall size and speed of the series' gameplay and was the second best-selling Genesis game. It introduced Sonic's sidekick and best friend, Miles "Tails" Prower, who followed Sonic throughout the game, and allowed a second
Sonic the Hedgehog forms, or both. The methods used to acquire the Emeralds and the end-results after collecting them differ between games in the series. Most early games require the player to find the emeralds in Special Stages, while some modern games implement the emeralds as a plot element. In certain games, such as "Sonic R" and the 8-bit versions of "Sonic the Hedgehog" and "Sonic the Hedgehog 2", the player is required to find the Chaos Emeralds within the zones themselves. The Master Emerald was introduced in "Sonic & Knuckles" as a plot element. It resides in a shrine on Angel Island