Here's a brief clip featuring an unreleased Sonic game that was produced in the United States by the Sega Technical Institute which was never completed. It features a number of changes to the familiar Sonic formula, such as a variety of different moves, as well as moving in a pseudo-3D space.
For more information, check out: http://www.sega-16.com/Interview-%20P...
BTW, I don't have the rom, so please, save your questions!