Take the 2D classic, keep the flat sprites for heroes and enemies and make the stage itself 3D. Toss in a few flashy camera tricks, and you've got a 3D Sonic concept anyone could love.
Now it's only a short video demo from the folks at pipocaVFX, not a real game, but the whole Paper Sonic idea is pretty brilliant. I'm sure its been done before, but never with so much class.
It's a nifty way to preserve the integrity of the original experience while providing the extra flair the kids love so much these days.
Now every time I play the first Sonic the Hedgehog I'll be tilting my head about, willing camera angle changes that will never come. Eventually I'll turn to drugs, and let them play a bit while I go get a sandwich.