This is very clever puzzle designs! I think it's the one of the most well-designed out of here! The music is pleasing to listen, and that comes from a person who doesn't really like bg music.
The types of mailmen are variative, though they all look the same. Perhaps add some visual clues to each of them? E.g left hand being bolder of left-handed or make cowards hold hands in shyness?
Very satisfying game! You did well!