What do you mean by realistic? I guess you could throw shading/lighting in, but then you're playing a 1D version of a remastered Mario Bros rather than the original.
I just mean some element of 3d. Anything. It could just be a blue sky in front of you and the faces of goombas and blocks are coming towards you as you walk/run forward (maybe you call that 2d with forward/backward movement). You would have up/down lookaround as well (no side to side obviously). The real question is: could you build this "world" with only data from an .nes rom?
