I wish I had the same problem so i could work with you on a solution together. Instead I just need to say "check your browser settings." :/
You can google a solution with something like:"How to make webgl games run on firefox/chrome/whatever."
Alternatively you can download the game and play locally (especially if you have windows)
You need to allow WebGL content for chrome. You can try this:
This is for playing the game in the CHROME browser:
1) Add a shortcut to Chrome on your desktop if you don't have one
2) Right click the shortcut and select Properties
3) Select the Target text box, go to the end, add a space and add --allow-file-access-from-files, like "chrome.exe --allow-file-access-from-files"
4) Double-click the index html file for the WebGL build and copy the URL in the navigation bar when the browser opens
5) Close the browser
6) Start the browser using the shortcut, paste in the URL you copied in Step 4 and press enter