I think Power Quest was a half-way decent fighting game back on the GB Color. It was pretty smooth and had a decent fighting engine. Probably the only good fighting game I ever played on a system that old, too.
I also think BioMetal, back on the SNES< was a good space shooter. Though it was really hard (I don't know of anyone that's beaten it), it played well. It tended to slow down when there is a lot going on. Lot's to describe, but overall was pretty good.
I know they are old game. But you said unknown, and they might be unknown because of how old they are.