Don't see anyone mentioning here that you can also play the piano with the ASDF...(etc) keys on your computer's keyboard. It was way easier playing it that way, rather than clicking with the mouse. Great job!
If you hit "0" or the button in the top right, it'll show a dashboard with settings and info on how to use it. I make that minimize from full size during page load as a vague indicator that it's hidden up there.
Also, I don't know if anyone notices the "info" link in the bottom left that scrolls the whole page down and shows some more info?
When I get chance I'll make a quick video of using it with the looper to perform a song.