This website finally went offline in 2018. Though given that it was using zplet, I’m guessing it stopped working a few years before that.
If anyone is looking to still play this game, I’ve rehosted it and a bit of the surrounding website experience here. (Adapted a bit so that it uses parchment and so that it works in modern browsers and on mobile.)
I got the z-code file from Paul O’Brian (who wrote a review of the game back in 2006). Assets for the surrounding website were taken from the wayback machine.
I also added a link on the bottom in the fine print that should open it up in parchment normally, if anyone would prefer that.