paraphrased from the designer's blog:
Inspiration for this adventure (an entry in the One Page Dungeon Contest 2013) came from the Oak Island Money Pit.
Like the real Money Pit, the intention is for the PCs needing to expend a lot of resources (money, time, possibly lives) to get to the bottom. This may require longer side quests to amass the necessary wealth, hirelings, skills, etc to do it. That makes it fairly difficult, and you'll notice that there is not much in the way of material reward for the PCs.
Quite unintentionally, there is a sub-theme woven in of dryness and water. Although this will work just about anywhere, it will fit particularly well in a desert setting.
This adventure is very linear -- almost to the point of railroading. Another aspect that may prove unpopular is that it seems to be one of those "death-trap" dungeons. That wasn't a design goal, but... yeah. There's really no getting around it: it's a bit of a death-trap dungeon.