Thank you very much for your feedback!
I have plans for a full game, so I'm gonna definitely work registering issues out.
I'm glad you like my music! Unfortunately, I didn't have time to write according sound effects for fail and success, so I used Kenney music jingles, but I will write my own for the future game.
I'm really interested what was happening with your playthrough. So, if you have some spare time, I would be happy if you could send me a video of you playing, that probably would help. Anyway, though, I'm gonna work on difficulty curve adjustment, like more training levels, adjustment to the music tempo, so it's slower on easier levels etc.
Thank you very much, I hope you will be back when the full game is done :)