Cat Mail Co. is a management simulation game where players act as a postmaster on Cat Island, responsible for delivering mail to feline residents. Players must sort packages based on various criteria such as weight and type, while also deciphering vague requests from cats. The game involves collecting packages for delivery by a Captain who has a variable schedule, requiring players to manage stock and organize items strategically for transport. As players progress, they unlock new areas and face increasingly complex delivery logistics. The game also allows for multiplayer interactions, adding an element of chaos to the cozy gameplay experience.