I'm beginning to suspect that this pocket kingdom is enchanted
On one hand, Pocket Kingdom is a welcome entry in the under-served "puzzlevania" sub-genre. It combines exploration-based storytelling and platform-puzzle mechanics in a semi-open world -- a rare pairing which I'd love to see more of.
On the other hand, this implementation leaves a lot to be desired. The story it tells is just a flimsy justification for some fantastical environments and mechanics - a threadbare example of a magical world trope - and its conversation-based exposition is more annoying than it is fascinating.
The open-world aspect of the game is hardly even worth mentioning, since the way forward is almost always a straight line. And if you do attempt to roam the map - like, if you mistakenly believe that there might be an alternate route to the next objective - attempting to backtrack through previously-solved puzzles is often a pain.
Meanwhile, although Pocket Kingdom's puzzles can get quite difficult, they aren't really satisfying to solve. Almost every puzzle is fundamentally about pushing and pulling blocks, to press buttons or stop lasers or create platforms; these mechanics don't significantly evolve over the course of the game. Even the scant few tools that you find later - a grappling hook, a rocket launcher - are still primarily about block-manipulation. (Also... you can't carry both of them at once!)
And despite Pocket Kingdom's relatively small scale, it frequently shows a distinct lack of polish -- like inconsistent menu controls, frustrating map navigation, overly repetitive background music, eye-crossing aesthetic choices...
... and at least one puzzle whose solution says a reward will come in a future patch. (It doesn't look like the game has been updated in a few years, so maybe don't hold your breath.)
Pocket Kingdom is generally playable, and definitely worth trying for fans of puzzles and interconnected world maps. But its world-building and puzzle variety, as well as its production values overall, are bluntly mediocre.
Better than: Qora
Not as good as: Toki Tori 2+
Definitely not as good as: Fez, The Witness (2016)
Progress: Got all the achievements, though I think there are still some items left.