I skipped over the practice levels, but I got around to play about half of the other levels.
They aren't quite as hard as some other levels here, but still each of them features a non-trivial and clean (i.e. no glitches or obscure tricks) puzzle. Mostly nice and short, and no hero-lemming tedious builder fests. And I like the design too.
I think this is a style of levels that can appeal to a wide audience of players: The casual player who wants to have some fun solving puzzles without using glitches or writhing in despair at the difficulty of the level, but also someone like me to have a break from the really hard levels and go for a somewhat milder challenge, or even a beginner who just learned how the skills work and wants to have a go at the first real puzzles.
What I really like about them is that they can be solved by just looking at them, and execution usually works at the first try.
That said, I think this is really a pack I can recommend everyone to play.