OP here: was afraid this would happen (good old HN hug of death). Unfortunately this isn't mine, just something I found, so I don't know if/when it'll be usable.
Basically it's a multiplayer text game with strong creation, collaboration and exploration elements. You and the other players inhabit a universe full of "vessels", which you can create by giving them a name and description -- so a vessel can be literally anything. Vessels can be infinitely nested within each other, and multiple people can child vessels within parent vessels. There also seems to be a small programming language with which you can give vessels behaviour, but I haven't investigated that much.
Basically it's a multiplayer text game with strong creation, collaboration and exploration elements. You and the other players inhabit a universe full of "vessels", which you can create by giving them a name and description -- so a vessel can be literally anything. Vessels can be infinitely nested within each other, and multiple people can child vessels within parent vessels. There also seems to be a small programming language with which you can give vessels behaviour, but I haven't investigated that much.
Two blogposts about the game:
https://emshort.wordpress.com/2015/10/06/if-comp-2015-paradi...
http://importantastrolab.blogspot.co.uk/2015/10/ifcomp-2015-...
Really sucks that it's not loading; I think a lot of people here would have gotten a kick out of it.