Doom was ported to the Super Nintendo using a Super FX 2 chip on the cartridge. It has most of the features of the full game, though with a few omissions, such as absence of sound propagation, probably due to the SNES having a much weaker CPU than a 386 PC.
One omission that surprises me is the lack of textures on the floor and ceiling. I would've thought that was exactly the kind of thing the SNES mode 7 was for.
Was it for some reason impossible to combine mode 7 with the Super FX 2, or was there some other reason for the omission?