Really polished! One of my favorites so far probably. Everything feels quite nice. Maybe the jumps are a bit unnecessarily hard, but i guess that has to be done to ensure only one player can cross them if they are near each other. I got stuck on level 10. Wasnt sure how to get one player up and the other across the wide jump. ^^
Since it is a jam, it may be a good idea to just unlock all levels since when somebody gets stuck they can still try the rest.