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.

https://crisp.home.xs4all.nl/lemmings/lemmings.html

I remember him, since he won a PHP contest of DownNOut (I finished second).

Another programmer had the same pseudo, but was working on the Atari ST.