Sonic the Hedgehog is a 1991 platform game developed and published by Sega for the Sega Genesis. It was released in PAL regions on June 21, North America two days later on June 23 and in Japan the following month. The player controls Sonic, a hedgehog who can run at supersonic speeds. The story follows Sonic as he aims to foil the mad scientist Doctor Ivo Robotnik's plans to seek the powerful Chaos Emeralds. The gameplay involves collecting rings as a form of health, and a simple control scheme, with jumping and attacking controlled by a single button.