I absolutely love this game! The base mechanic, the mapping, the visuals, everything is amazing. Although, I have a couple suggestions that I think would help with trying to get better at the game:
-Toggleable miss/barely counters would be nice, because sometimes it's hard to hear the barely noise over the music, which can be annoying when grinding for a P rank.
-I think a practice mode where you can set the speed of a song and/or start at a specific part would be helpful, since sometimes I need to learn the pattern for a specific part but have to go through the entire song to practice it just once.
-A mouse sensitivity adjuster in the settings could be useful.