[andrew_eu]

Super interesting question.

I didn't, but found this [1] 2001 paper without much difficulty. Getting much out of it is more difficult. As I understand it, the complexity measure they propose is somewhat related to the difference of arctans of turns to take "forward" vs turns to take "backward", summed up for every fork and scaled with some length measurement. There are definitely plenty of other complexity measure though (e.g. number of forks, number of incorrect paths, etc) -- correlating that to practical difficulty is less straightforward.

[1] https://archive.bridgesmathart.org/2001/bridges2001-213.pdf

[bee_rider]

Ah, I’m glad that somebody at least tried to come up with a measure that sort of… matches the human eyeball intuition of what a difficult maze is, even if it is mathematically a bit funky.