The webpage is loading an incredible amount of .js files which all look identical (https://margeux.com/rb338/boxedwine-firefox-20261103.js, looks like Emscripten JS shims), but then also loads two massive blobs (one is 100 MB, the other 150 MB). I'd at least check what's up with all those .js file downloads, that looks like a bug tbh.
First start takes very long btw on a 50 MBit connection, most time seems to be spent with this same small JS file that's downloaded many times, I'm sure this could be massively optimized.
It's a very impressive clone, works very well (pre AI!). The only downside is it doesn't have the "Space Pigs" theme.