Silver the Hedgehog is a rival boss in Sonic Generations. He is a boss in the modern era, from Sonic the Hedgehog (2006). His battle is a road area in Crisis City.
His battle is mainly a race. He throws debris at you. You have a chance to hit him after he gets debris, piles up debris, etc. Before his final hit, he launches a giant boulder of debris at you. The battle is won, after.