Ohh, wow yeah that's really helpful and insightful! I have no background in that area so I was just making guesses as to what the difficulty should be. But it seems I was pretty off haha. Maybe I should've started at 2x2 to allow the player to unlock more upgrades before getting to the later parts. The "test mode" idea is really good, definitely being able to freely play around with it could add a lot of options to explore one's cognitive abilities. Thanks so much for all the feedback and suggestions!