May or may not work on Mac. But I use Maxthon Portable at work to access the web GUI for old, legacy devices that were designed with flash/java interfaces.
It does have a Mac installer, but can't be sure whether or not it'll actually play the game. Still, worth a shot.
https://www.maxthon.com/download/previous-version-browser-free-download/
Ah shoot. Two other browser options are 360 CHROME BROWSER and Maxthon 5
According to this forum post, these browsers support most modern websites as of August 2020
If neither of these options work start a new thread in r/windowsxp. Users in that sub have more experience with EOL web browsing.
Pretty sure Maxthon does. It's like the most common not-talked-about web browser, but it's pretty good and I sometimes use it myself. Back in like 2015 it was the most HTML5 compliant browser out there.