Thank you for the kind words! Well, it helped me a lot to playtest LOK with various people, seeing where they struggle and streamlining those bits. In terms of the puzzle design, it's always the case of being as basic as possible in presentation of a new element and then making it more challenging with other puzzles, where the new element is already known. So yeah, there can never be enough of simplicity and accessibility - you can always ramp up the difficulty with later challenges.