[jmstout]

Sounds like it's quite the artful balance between procedurally generated and manually curated content.

A bit (but just a little) more information can be found here: http://www.thesixthaxis.com/2014/06/25/crafting-the-endless-...

[pokpokpok]

I disagree, I think that it's the procedural generation that needs to be done artfully! Unfortunately the tools and experience to be creative in this medium are a few years out :)