Weird -just tried it on chrome and it did the same thing to me! So, I started looking into the issue and went back to the tab I had open with that game and the game just started working! My guess would be that chrome needs a bit of extra time to load it or maybe leaving the tab open and then going back made the browser refocus on the game or something. Sorry, I'm not sure why it's doing that or how to fix that but now it works for me right away now even if I close chrome and open it and go straight to the game. I hope trying that works for you too!