Richard, Final fight programming on amiga was good with many clever ideas. You did with what you got. The game i love the most from you is Double Dragon 2. Not only the amiga version is excellent, but the amstrad CPC version is top class and even above all the other 8 bits release (since it's an amiga port).
Shinobi and FF got bad graphics, because those who ported them were not professionals (if i remember well).
BTW, would you be interested with final fight Amiga code ressourced ?