UNO FLIP! is a version of the classic UNO card game that features a double-sided deck with a light side and a dark side. Players start with the light side, but a special FLIP card can be played at any time to turn the deck over, switching everyone to the dark side with new colors and action cards. The goal is to be the first player to play all the cards in your hand, with the game continuing until a player reaches 500 points.