[From Wikipedia https://en.wikipedia.org/wiki/Sonic_the_Hedgehog_4:_Episode_I]
Sonic the Hedgehog 4: Episode I (ソニック・ザ・ヘッジホッグ4 エピソードI Sonikku za Hejjihoggu Fō: Episōdo Wan?) is a 2010 episodic platform video game in the Sonic the Hedgehog series. The game was developed by Dimps, with assistance from Sonic Team, and published by Sega. The game was intended to emulate the original Sonic the Hedgehog titles on the Sega Genesis.