I kinda hate you for making me waste so much of my time on this thing but I have to give it to you, it is addicting! I adore being able to see all the data, I adore the colour choices and how clean the UI is. I'm a sucker for that data board in the round stats and I keep staring at them while I absolutely mash my fingers to get on that leaderboard.
Small negatives: I did manage to break it a few times, once where the 'x2' combo stayed on while it was recharging, and once where my 'rest your fingies' just dispeared. I also don't fully get the flipbook thing in the top left corner? I don't get what it represents or how it works, but when I don't try to open it it looks pretty in the corner.
I tip my hat off to you, this is simple but incredibly well done, smooth and addictive!