The Aztecs are attacked by Alien invaders! Your goal is to accumulate points by gathering the inhabitants of your city and trying to protect them from the attacks of flying saucers. Each turn, starting with the first player, you will choose a face-down deck of cards from 8 then, simultaneously, choose a card that you will play, paying attention to the time of day indicated on it. Whoever is the earliest will play their card first and become the first player in the next round! There are several families of cards: the Warriors, the People of the High Society, the Villagers and the Agency. Each has its own scoring or particular effect. Some allow you to score points, others allow you to trigger flying saucer attacks. The game ends when a certain number of decks are empty or a certain number of flying saucers have been played.