There are a number of Myst fangames in existence. I have my own fangame plans on the backburner - including a remake of my old, now-pretty-broken fangame 'Sehv T'devokan' from 2004 and a port of my Uru fan ages [a five-fan-age expansion!] as a standalone game at some point in the future. But all this stuff will be filled in later on.