At first I have to say I was a little unsure of how good of an idea it was to make a game entirely based around quickly inputting sequences of buttons using an input device that doesn't fully correspond to the buttons being displayed on screen, especially when it involves very slim margins of error. Having beaten the game, my initial feelings were pretty on the money, since it does give the game a bit of a frustrating difficulty.
What I also have to say is that everything else about the game, the visuals, the story, the fact that there even is a complete story, the design of the fights and how they incorporate dialogue sometimes, more than makes up for it. I particularly enjoyed the parrot calling out the next attack and the way the fight twists that concept around afterwards, and the way the palette swap is saved up until the last fight in order to break patterns, change the mood and up the intensity. That palette swap with the music change was a great vibe, very "oh shit it's going down now", and that was probably my favorite music track too.
Which brings me to my next thing, the music. I feel that it was really impressive in how complete and varied it was, and sometimes the mood and the vibe are really top notch. It's well made rhythmically but sometimes it just has some harmony that just sticks out a whole lot for me, personally, like something just doesn't quite sit right. You should still post it somewhere though.
Overall, the gameplay is pretty basic but you did a lot with it for what it is, it's a bit too hard and fights are maybe a bit too long, but it's a very impressive complete experience. Great job!