I loved this! Thanks so much for making it! I really enjoyed learning and playing around with the mechanics, makes me want to go play Stephen's Sausage Roll and wish for a level editor for this. I did find a niche mechanic with the monster that I didn't see come up in a puzzle, so I threw together an image of a level as a proof of concept just for fun. The button (de)activates all the gates.

The solution is (rot13):
YQYHQHEHYEEQYHQQHHHHHHQYYYYQQQQEEEEEE (Lbh pna chfu gur zbafgre fnsryl jvgu lbhe onpx)