http://loopsofzen.co.uk/ has been updated to make the game more fun. This has involved subtle changes to the bias for randomised starting positions and based on feedback from users. Basically, far fewer single endpoint nodes.
The site is only available by IPv6 though. If you can't get to it, complain to your ISP.
Also works as http://[2001:8b0::102]/
Perhaps tell your ISP that URL does not work?!
P.S. Happy to acknowledge Arend Hintze for inventing the game. He does not appear to have patented it though, hence our version...