I haven't actually done it yet myself, not have I properly looked into it yet, however I know that there are the red pawning badniks that come out of the wall, I was thinking there was a place where you could roll into them, go left, then go back to them to make them respawn, then go roll into them, and keep doing that, as long as you don't jump, it preserves your combo, so you can get a higher and higher score, the place I was thinking was after the first elevator btw, no idea if that's the place it works though.
