When I click "play" the music changes, but the visual display does not, and it doesn't respond to mouse input. Firefox 72.0.2
Good to here it's working for you at least in Chrome
We tested it in the same browser as you have but it Win10 and it's working normally
Not sure why the differences between OS :(
Perhaps it has something to do how they implement WebGL?
BWT: Hope it will get fixed with the new Firefox 73 that just came out :)