The truth is, I do not like puzzles. I often find them tiring, hard to navigate, and unrewarding. Any time a riddle or a puzzle comes up in the game, I completely check out mentally and wait for someone else to figure it out.
I'm happy to say, despite who I am as a person, this PDF has a lot for you. Here's why:
It's got a hook. The puzzle dungeon is not only a title, it's a PLACE. A physical (or metaphysical) place that your party can be picked up and dropped into for fun. Actual FUN, can you imagine? There's a story behind why Aenigma wants adventurers to partake and the party is graded based on their performance to offer more complex prizes - from some gold to a huge amount of gold and a magic item. The whole book is self contained and presented as an adventure - the puzzles themselves are in an appendix for you to use elsewhere if you like.
Low frustration. From my time playing this adventure and looking at these puzzles, they're not going to make you pull your hair out (though one of them makes absolutely no sense to me, personally because 'magic'). Each puzzle is given a difficulty and each puzzle has multiple fail states - your party can fail a puzzle multiple times and still get the full score for the dungeon so long as they don't require hints from the kobolds inside. Each puzzle also comes with a tips section to aid you in describing the puzzle, the handouts (some of which are mandatory - be warned), and the setting. The whole point in design, I feel, was to make the puzzles NOT cause the party to feel stupid or inept. They're cumbersome and sometimes complex, but because they can be brute forced sometimes or worked through without hints - it works.
Variety. When we played, there were 2-3 puzzles that people just clicked with and understood completely. On the other hand, there were a few that people couldn't wrap their heads around at all but were ODDLY EASY for others. That duality is not black and white - it's the perfect gray area in terms of puzzles. If only one or two players figured out every puzzle, then you'd have a whole table sitting there doing nothing. Word puzzles, spacial puzzles, operation/order puzzles, cryptography - there's a lot of variation in each one. Considering this is an introductory volume, that sets the stage for a lot of other versions of each.
Overall, I think this is a solid purchase for many. A cool black and white aesthetic with splashes of color for the puzzles, a weird and wacky story of a peculiar dragon, a decent layout with space for notes, well-made handouts - it's got everything you could ask for in a puzzle supplement. That's not to say it's flawless or perfected - there's very little team play in this volume, no puzzles that require multiple people working in tandem - it's more catered to massaging the players' brains than the PCs', but that works very well for smaller gropus. The big plus is - you'll not be recycling the same 3-4 reddit posts when looking for inspiration, thank god. Pick it up.