All I did was just grab the SMb3 mario sprites and edit them.
Screenshots:
this is, well, just an edit as you've said? it doesn't change enough to be accepted either. even if it did, a replacement for GFX00.bin is missing-- which includes some player graphics. this also looks unpolished - big mario's head is misaligned when standing, some parts of the outlines are miscoloured or missing (see: ducking pose, small mario falling pose, flying poses, various big mario walking/running poses...)