Cahoots Card Game
Cooperation is key in Cahoots! Play cards to one of four piles by matching color or number. Work together as a team to complete a series of goals — without communicating what's in your hand. Can you make all piles purple or green? Every card lower than four? All cards add up to ten? There's only one way to win before time runs out: Play in cahoots!
Note that the original Cahoots has a player count of 2-4, while Tippi Toppi (Schmidt Spiele's licensed version of the game) has a player count of 1-4. Notes a Schmidt editor: "It is works quite well as a solo game, too."