Poor game. This game has almost no redeeming features unfortunately.
I'm going to start off with the most obvious thing, which is your sound. Everything from sound effects to music is just awful, especially your collect noise. It's really, really loud and annoying. Your attack noise was so bad it almost made me not want to attack anything. Your music consists of a really short loop that just continues on and on, which is generally just a poor soundtrack. It's just boring and repetitive.
Your graphics are really bad. Pixel graphics are a bad idea in general. People do them because they're too lazy to do anything else. However, occasionally, somebody comes along and manages to do them right. You weren't one of those people. Your graphics just don't fit together and aren't charming at all. It just looks really unattractive and kind of hurts the eye because everything seems a little bit too bright and there's too much color variation. Trust me, being talented in art is difficult, but graphics is not something that can be brushed off, especially in flash games. Your animations are just as bad. The animation for attacking is so bad it's almost funny.
If that wasn't bad enough, your game play is so basic and boring that it's no fun. Picking up notes feels like a chore. Your character moves so slow it's brutal. In my opinion, just remove run from the game and have your character moving at the run speed all the time. Because no one is ever going to need to move that slow at any point in the game. Your combat can hardly even be considered combat. There's no actual meat to it at all. It's just spam the Z key as much as possible. I mean, your enemies don't even move. The combat system is literally so bad it might be the worse combat system I've ever seen in any game. When you hit something, it should be knocked back a little. One of your main issues is the fact that your controls are really weird. WSD to move, SHIFT to sprint (if you really want to keep it in there), Left Click to attack. That's a hell of a lot smoother and easier to control.
The worst part of this game is the fact that you didn't even redeem yourself. No story, no comedy, no dialogue. It's just as simple as it can possibly be, with bare minimum effort, and it shows. I feel like you were trying to mimic like an old NES game or something, but you failed miserably. This game was just a train wreck. Next time you create a game, you really need to put effort into creating an original game.