Music is great as everybody already knows. The iconic overworld map music is very good, and so is the dungeon music.
Replay appeal is there too with the second quest.
Story is practically nonexistent, but such is the case with any NES game, really.
My one and only real complaint with this game is that the final boss is pretty lame, as he's invisible and you just have to stab around randomly.
Not going to do the thing where you break up and rate each section of the game as I don't really agree with that rating system (story plays a larger role in some games than others, while both can remain great for example), but overall I'll roll with 9/10 for an amazing game.