You just need the index.html file and the main.[bundle_hash].js file. You can scrape out the Google Tag Manager import from index.html if you want, though I didn't check to see what tracking it was importing (probably basically analytics).

But so long as you have those two files in a folder, you can open index.html and it'll work fine. My friends and I have been putting in joke words in a shared clone for each other and hosting it on GitHub Pages.

Yes, the entire app is in the front end. It's not talking to a server to get new words of the day or checking answers. When you click the link and the game loads, it just loaded everything you needed to play it now, tomorrow, or some day in 2025.