Huh, I've never seen it played, nor read it, or even really heard much about it before. Judging from the DTRPG page and the number of supplements and such it has proven popular somewhere though. Not to say that makes it a "Good PbtA" I guess. Lovecraftian style horror seems like a rich sort of vein to tap though. The GM has basically infinite ways to turn the screws, and for the players its a pretty classic "and now the even worse badthing happens!" which is totally genre appropriate. Again, not to say this particular game managed to pull it off well.