It'll be hard to argue this isn't one of the best of the jam, let alone best for the Shadowdark entries. One could nitpick that the sparse text and the fairly complex pitch of this adventure might be a little bit of a lift for a GM but it's just art all the way down (and that art is also art, really good art).
If anything I don't know that I've experienced anything Appendix-N-ish that feels like this one does. The underworld delving, bureaucratic cubi, etc, give me some Urban Fantasy vibes.