Your 10-year-old is smarter than me because I couldn't figure out what to do in level 19, haha.
Hello. Thank you for your interest with my game. I would like to inform you that someone has posted on Steam many video so as to explain how to solve each level. Maybe it is too easy for you, but you can find some help. Take a look at the community forum by the Theorem main page. I wish you the best. Have a nice day ++