Of course being 3d presents a whole load of other challenges such as how to shade the ground so you can always tell what the fall line is, how to keep level design/editing simple and shareable, figuring out how the game can assist you with landings, how to give the player good control over the camera if they want it... the list keeps growing the more I toy with it.
Still lots of work to do and problems to solve if I decide to go this route.