These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
What's really impressive about the music in this game is that the loops are quite short ("Bloody Tears" is a repeat of only thirty seconds; others are even shorter), but what's in those brief spaces is so good that not only is it not criticized as repetitive, it's downright beloved—the series' Awesome Music page names almost every track.
Game Breaker: The Golden Knife. Although it's prohibitively expensive to use to just mow down everything in your path, it's powerful enough to render any enemy - including Dracula - harmless.
Most Annoying Sound: By the end of the game, the beeping that accompanies dialogue is probably gonna be ingrained in your head—WHAT A HORRIBLE NIGHT TO HAVE A CURSE—in a bad way.
Polished Port: In the reverse of what would happen to the next game, the soundtrack to the NES version is widely considered a massive improvement over the original Famicom Disk System version, which is generally hated by fans due to the tinny, whiny instrumentation, and a distinctly lacklustre version of "Bloody Tears."
Scrappy Mechanic: There is no way to speed up the text box marking the change from day to night and back. And you'll be seeing it a lot. Fortunately time stands still when you're indoors.
That One Puzzle: The infamous puzzle where you have to stand in a certain spot with a certain item and wait for a tornado to come and carry you to the next area. There are hints to the solution in the game, but the sheer insanity of it definitely qualifies it as this.
Vindicated by History: Maybe not the game itself, which still tends to be regarded as the weakest of the NES trilogy, but the gameplay style it pioneered would ultimately displace that of the franchise's original style, with Symphony of the Night.