What's up! This is really good for your first attempt! You should be very proud.
The input feedback for when I’m pressing keys feels very unintuitive, and you cannot customize the control scheme. I also wish the game wasn’t titled Untitled Rhythm Game. I know it’s supposed to be funny. It would be easier to understand if the controls were explained in the description as well.
The controls are something I don’t like. There’s a massive delay in the keystrokes, and the input feels off. The music plays and there is no interactivity which is confusing. First level should be super easy. The game starts incredibly fast, and there’s no clear or presented story as to why things are happening. That said, this game has a lot of potential. You’re skilled at making games, and you’ll only get better—so keep going. However, currently, it has flaws that can be improved. The game’s identity feels too close to Friday Night Funkin’ and should establish more of its own identity and premise, which I believe you can do.
I can’t make games as well as you, and you do have a lot of skill. However, stupid people like me will play your game, and if stupid people like me don’t like it, they’re not going to give you lots of money or make you rich. That is my advice.