couple of suggestions:
1. note speed customization (rn it's too slow for my taste)
2. note hit window customization
3. note line amount (for example 5 lines instead of four)
4. note streak (kind of like in clone hero) + notification if FC'd
5. option to turn off note missed sound
overall i would like to see more customization
aside from that i look forward to this game as there are not much music games that work not on already made maps but generate them from music
also the 1$ price on sale is pretty much free so grab it while you can because it might get good updates