This small adventure is great as both a one time adventure in Theros and as a supplement to your Theros campaign. Due to unforeseen circumstances with one of my players I decided to quickly run a side adventure in my Theros world with the other players. The way the adventure is written allowed me to set this up in a matter of hours, of which most was spent recreating the map with DungeonDraft (which is not required).
The plot is straight forward but very fun to both run and play, with many of the elements we all love to see in our games: exploration, diverse combat, puzzles, and riddles. While it fits very well into the setting of Theros, which has godly conflicts like the one in the adventure around every corner, it is simplistic enough that I can foresee no problems adapting it to a different setting.
I am a fan of the adjustable encounters and ran into no balancing issues even though I was running it with far from an average party.
To give some feedback, all the rooms have a very small description for the DM to read out yet a few of them fail to describe some major elements in the rooms. I understand these example descriptions should be short but since I did not have much time to prepare it was a bit frustrating to read out the description only to find out one paragraph later there is some major element of the room that the initial description does not mention at all (see "Nyxborn Dormitory" and "Unbreakable Reliquary").
The last point I would like to make is that Appendix A with the monster stat blocks could have been structured better. If the 4 stat blocks can indeed not fit on one page, the Naiad and Anvilwrought Crayfish should definitely be on the same page since they occur during the same combat encounter, to prevent unnecessary scrolling.
Overall I can recommend this to everyone looking for a fun Theros adventure.
[5 of 5 Stars!]