VHS footage of a cancelled Genesis game called "Segapede" (later "Astropede") has been uploaded by SEGAbits. This prototype was developed at Sega Technical Institute and was intended to be connected to the Sonic universe. This footage is from former STI artist Craig Stitt, who had previously worked on Sonic 2 and Sonic Spinball. The level graphics shown may look a bit familiar to you.
For more info, and some concept art, check out this article from SEGAbits.