A big improvement over 0h h1. I never felt like I had to think when playing 0h h1. Every puzzle was solvable by searching for a series of patterns that had an obvious solution. 0h n0 seems to be just complex enough that sometimes you actually need to think about the problem. At least that is the case so far.
It requires a non-zero but pretty low level of "executive function", but significantly less than most logic puzzles.
In particular, a few times per game, I have to apply a little bit of "frontal-lobe" or higher-level skill to prevent myself from losing my patience for constantly applying the lower-level or "perceptual" skills required by 0hh1. In particular, I have to apply frontal-lobe skills to resist the temptation to engage in the "wishful thinking" of falsely believing I have perceived a correct next move to make.
(I engage in 0hh1.com mostly to relax or unwind, not to hone any higher-level skill.)