That is just a rehost, as I know the person who created that, a Dutch guy. The original is not hosted anymore due to Brein, a software IP/piracy agency.
Such an interesting bubble of time. JavaScript, CSS and the ability to modify the DOM… but no AJAX requests. I remember using iframes to load remote content. What a mess.
Trip down memory lane, I just remembered the sadness I felt when I finished the level where you have to use blockers to guide the descent but when all the lemmings are saved, you have to self destruct the blockers to win.