This doesnt work on my android
I tried it out again to make sure it still works. It does, but with a catch.
When I downloaded the game using Firefox on android double-clicking the .apk file tried to open it in a random app, rather than install it.
The issue is that android now only allows apk files opened by certain apps to be installed. If the app isn't allowed to do installations the apk will just be opened by some random app instead. So the solution is to download the apk with your browser, but then run it from the file manager. That should lt it actually install.
TLDR - Open the APK file from file manager, not your browser.