This is a video demo of a beta version of 3DNES, a work-in-progress Nintendo emulator that renders classic NES games in 3-D. It's by no means perfect, but it does look promising. Kind of like the halfway point in a video makeup tutorial. You sort of look like a clown now but I believe in you.
Unlike SNES games, which have four background layers, NES games have a single layer for the entire background, making automatic 3D conversion tricky. According to the developer, 3DNes is based on an algorithm that analyses and separates flat backgrounds into singular, 3D objects. It's not just simply stretching out pixels on another axis, either: round objects are rendered as spherical or tubular shapes.
There's a video of a handful of games being rendered after the jump including Contra, Mega Man, Zelda II, Super Mario 3, The Legend Of Kage and Castlevania. Some definitely look better than others, and some just look pretty bad. Kind of like people. I remember having a conversation with my dad years ago and I asked him what percentage of the population would be considered attractive, and he estimated around 5%. Then I asked him if I was part of that 5% but he just gave me a sad look and wouldn't answer.
Keep going for the video demo.
Thanks to Aaron, who agrees everything that wasn't originally rendered in 3-D should be now because this is supposed to be the future, dammit.