Robotnik, a scientist who has imprisoned animals in robots and seeks the powerful Chaos Emeralds. Players control Sonic the Hedgehog, who can run at supersonic speeds Sonic sets out on a quest to defeat Dr. It was released in North America on June 23 and in PAL regions and Japan the following month. Sonic the Hedgehog is a multidirectional scrolling platform game developed by Sonic Team and published by Sega in 1991 for the Genesis/Mega Drive.