Cocoron is really good. It plays largely like Mega Man, but the gimmick is that you build your characters from various parts you have access to, each effecting your stats. One of the best Famicom games to never come out here.
Another that you might consider is Layla. It isn't anything amazing, but for 1986, it has a surprising amount of content. It handles a little weird, like your character is on roller skates or something, but it's decent once you get used to it.