SNES Alpha 2 was impressive technically, but gameplay-wise it was shit. It barely played like the arcade/PS1/Saturn ports and was slowdown-ridden.
SNES Mickey Mania looked mostly similar to the Genesis version, but had a higher color count and some extra layers of parallax here and there. But as the gentleman who replied to my post explained, it suffered due to not being natively designed on the SNES hardware.