Some people like a hell of a challenge, which is one of the reasons the original Ninja Gaiden games are celebrated to this day. With unlimited continues, theoretically anyone can overcome them with enough patience. At least in my eyes, however, a lot of the difficulty is kind of cheap and lies in certain types of aggravating enemies and their placements across the levels. It could be a whole lot worse though, looking at other dogshit from the time like Battletoads that people will still fight tooth and nail for. I still appreciate this trilogy of games at the end of the day, not just for being pretty damn solid games underneath their unforgiving difficulty, but also for being some of the earliest games to bring story and cutscenes into the spotlight and by extension the mainstream of the medium. Definitely more forward thinking than a lot of people seem to acknowledge.

Tecmo would port the three Ninja Gaiden games over to the SNES in 1995, as a three-in-one deal. Not a lot is done to make improvements though, and I would actually have assumed they were the same code if not for the fact that Ninja Gaiden II's screen transitions (or lack thereof, initially) were altered to match the other entries. The only things that really change here are the music, which is weaker than before, and some rather minor details added into the spritework. For the mid-90s, it's pretty thoroughly unimpressive, and often actually lacks the same punch in the originals' presentation. I would just grab ROMs of the NES releases if I felt like playing them again.

I'll give credit where credit is due though, I'm immensely thankful that III was mercifully nerfed back down to its JP release rather than keeping the NA version's awful changes. Nobody back then should have been subjected to Ninja Gaiden III with limited continues.