Hagane. Not the best remembered of SNES games. It's a late-era platformer/actioner that was halfway between ripping off Shinobi (the weapons, acrobatics, enemies, plot) and Ninja Gaiden (the sheer 'fuck you' attitude to difficulty). Good pedigree to have if you're a sidescrolling platformer about a one-man ninja army murdering a small horde of mooks.