Very good game my dude! It was lots of fun to play and the different songs are all very well made. The visuals are also very nice and overall the game reminded me a lot of OSU! ~
The difficulty felt good aswell! I managed to beat the Final Track on Hard with a score of ~30.000 and it felt nicely challening. I noticed that its easiest to get perfect score by simply spamming left click which i think could be improved - ideally you would get a perfect score if the circles align and THEN the click is done.
The "Limited Space" interpretation could be improved upon in my opinion.
All in all an amazing game! Good job