Yeah those 2 guys with the arms, second underground base stage I believe, both very annoying because they sandwich you in between if you don't manage to get over them and corner them instead. The last boss, Achillies is indeed a pain but strategy is the only way to take him down, button mashing doesn't seem to work against him like it can a couple other bosses.
I don't bother with it in MAME these days, it's in a Capcom Classics Collection, so is Tiger Road. Ghosts N Goblins/Makaimura is in it too, but it runs faster than it should, so PS1 or Saturn for that conversion.