Is Mode 7 required to make the SNES do mosaic? The "mosaic" in Metamor Jupiter (more just just straight blockiness as mosaic actually is a de-resed version of something already existing) looks pretty bad. The real mosaic in New Adventure Island is much better (and a true mosaic), but mosaic still sucks on any system. There is only one effective use for it, and that is when you get shocked Then it looks good and is a well-chosen effect.
Speaking of Mode 7 and how each scanline is just scaled differently than the scanline below it to make it a perspective, why didn't they ever include walls? Granted, this would be tough to do if something were to rotate, but, say, if you were just going forward, couldn't you have a road and a "wall" or building or something at the end of that road which also scaled as you get closer? I never saw a SNES game do that. The "tilt" of Mode 7 must have been part of the devkit software, there is no way it had to be done manually. And I'm sure the software treated it as a tilt as far as the graphic designer was concerned.