Looks great but please don't forget something players can identify with - like Axel and Blaze.
Sprite sizes in Project Y probably should be rather Golden Axe III-ish to Bare Knuckle II-ish so you can squeeze some more enemies on screen at once. A larger sprite size would drastically reduce the playfield and limit the number of objects you could display at once. Bare Knuckle III sends enemies away, out of screen during a fight scene to give the impression of more enemies on screen at once.
Another hint: A good 16-bit brawler needs a "returning thug" - like the footclan soldiers in TMNT or the Galsia/Donovan/Signal/Biker gang in Streets of Rage. They're literally faceless (Signal, Biker, footclan soldier) so they can be used again and again, with the only difference in appearance being the colors of their clothes (Signal, Biker, footclan soldier) or the weapons they're holding (Glasia, Donovan, Biker, footclan soldier).