Hey. I'm glad you enjoyed the parts you did and thanks fro the feedback.
You might be right about the category matching puzzles( the ones called pattern recognition lessons in game), I kinda made them stricter than other levels for no particular reason by not allowing some mistakes. I'll need to think about this, likely I'll add some allowance for mistakes depending on how complicated and long each level is.
One other thing I'm planing to start adding in the next update to solve a similar issue is making some alternative ways to unlock further levels. I know not everyone would enjoy each type of puzzle equally so for example I will be adding a feature where you can open a lesson way on the left side of the level panel by getting a high enough score on a lesson that is on the right side of the panel, potentially skipping several levels for the unlock.
Anyway, let me know if you have other feedback, this sort of stuff is helpful.