Okay, so I got into a vibey lil flow state playing this the second time(next day). Felt good was fun.
The main constructive criticism is the contrast on the player. I feel like the player should be clearly visible as others have said. The color indicators help to centralize the location but I still want to see the player more clearly.
One other thing was the game can be cheated by just spamming all the controls. Maybe a debounce on them would prevent such cheating? Anyway good vibes def fit the theme. The dancing bgs felt fun; I was worried they would distract but it was chill. So yeah your experience design hit the mark for me.