Ninja Gaiden II: The Dark Sword of Chaos

On the gameplay level I have to admit that this is a pretty typically lazy give'-em-more-of-the-same sequel. But it just so happens that in this case what they're ladling me more of just happens to be pretty damn good, so the end result is still perfectly playable. The game also has the unique distinction of having probably my favorite opening cutscene of the entire NES library.

better but still too hard

Well, at least you can climb now, and they've given the jump a bit more airtime, but they've also made the hitbox on the sword slash a bit less cooperative. Enemies are about as obnoxious as ever, and now you've got the occasional stage environment gimmick to bog things down on top of that. It's fine if you especially like this particular sort of challenge, though I'm not sure how much I do.