I'm a newer DM, so take this with a grain of salt. The setting (creepy carnival) is undeniably fun, and ripe for all kinds of roleplaying. And it was appropriate and enjoyable for a group of mostly newer players. But as the other review for this mentions, what drags it down is the dialogue in the tavern (too many NPCs with too little important info to share). My PCs felt like they were missing something, when in fact there just wasn't much there. Then exploring the fair, while more fun than the tavern, can suffer from creating too much downtime before the first combat encounter. The tavern is more at fault than the fair, though I think it's reasonable to say that whatever dialogue is spread throughout numerous tavern/fair NPCs and locations could easily be streamlined into 1-2 discussions or stops. If I were to run this again, I'd have them arrive at the tavern at night with one NPC (Aelia) awake to fill them in and push them off far more quickly, and would consider some tighter "rails" at the fair itself.
Once my PCs got into the mirror maze, this was a blast. I improvved a mirror teleportation puzzle that they solved with some rope and spellcasting, and the final encounter with the cool mirror-based lair abilities was satisfying.
[3 of 5 Stars!]