OK, I think I can say something useful about it:
This is a game whose rules and goals are hidden from you, and the long-term narrative arc of the game — the narrative itself — is you figuring out what the rules are. Several times, a new “aha” moment changes your experience of the whole game world, and for me, at least, that narrative experience wasn’t just the frustration-satisfaction cycle of a solving a puzzle. This is a game that made me •feel• a whole lot of somethings.