[maxwellito]

By default (with chrome) a service worker will cache the app for offline use. If Chrome didn't asked you, just add the page to your homescreen.

[Markoff]

i am using Brave browser, there was no popup but it seem to work offline

[maxwellito]

Brave is based on Chromium. With a bit of chance, the service worker should be working as fine. That mean even offline you can access the page (by going to the URL as usual).

But I know, the UX sucks to access such a silly game :(