I’m partway through the actual book The Night Circus now, after having played Failbetter’s intro game quite a bit. It’s a curious experience on two fronts. First, the book has a number of short passages written in second person present tense, describing “your” interactions with the circus — pieces that fit very well into game narration terms. It feels as though the book were tying into the game as well as vice versa. And second, because I encountered the game first, that experience has a sense of primacy. It’s pleasing and reassuring whenever I read something in the book that I recognize from the game, and I think, “oh, yeah, here’s the ice garden” or “finally I found the living statue.” The world of the Night Circus feels more… for lack of a better word, more fully-dimensional than fantasy worlds in books typically do, because the game has given me a sense of the spatial and tangible existence of the circus.
Which I guess is a roundabout way of saying that I feel like the game has actively added to my enjoyment of the book, and not just in the marketing sense of making me aware of the book in the first place (which is true also).