Yeah, the controls are very confusing with so many buttons. It also felt like in every menu there are new input conventions, it is definitely worth unifying (e.g. remove R button completely and only use e.g. J and K to select and cancel/go back).
I think simplifying the game by removing half of the moves and most of the modes would help to focus on the basics. Right now it feels a bit janky with so many half-done features (like the special powers on Space that are not even mentioned anywhere, or the game going gray for a couple of minutes after selecting "continue" after loosing in arcade mode).
The visuals are great, good job doing the movement shadow effects!
Can't see any mention of the composer. Well done handling Vocaloid, it is quite rare to hear them nowadays.