I GMed this scenario for a party of 4, high tier.
The party really liked interacting with the Albatross and Owl, and the Wizard was super stoked to be allowed into a normally restricted archive. Madame Koi's memory issues also brought some joy, and the monsters they fought based on the riddle they were piecing together were intriguing.
However, the fight with the Worm and Bird was a bit too easy, and similarly the tooth fairies were a minor annoyance. While it was interesting to have them explore a flooded archive, I think every room should have had something more engaging in it. Apart from the fairies, the other three rooms downstairs only have items to find. Granted, the Darklands Precepts is a rather cool tome, but nothing even comes from a PC reading it.
So, in total, of the about eight rooms in the scenario, only about four and a half have anything interesting in them. What's there is rather nice, though, and the PCs enjoyed trying to crack the riddle, which is ingeniously written to be super simple yet seem more complicated as it goes on.
All in all, I'd recommend a lower level group to perhaps bring some zest to the fights, and to focus on the bizarrely fey logic and characters over the combat. It's better than average!
