The Tweegles are monsters from another galaxy, come to invade the Earth. Unfortunately for them, once they hit the ground, nothing is on their scale. They are frightening and huge monsters on their own planet, but are only as big as mice on earth. They land in an everyday house, full of traps for them: electrical sockets, children with scissors and stamps, insects and cleaning products... Twenty-five action cards – each showing a tweegle that has been hit by one of the "traps" – are laid face-up on the table at the start of Tweegles, while the twenty-five tweegle cards are shuffled and set aside. Everyone plays at the same time. One tweegle card is revealed from the deck, with the card showing one of five tweegle types and one of five possible actions, symbolized by scissors, a mosquito, an electrical socket, a stamp and spray bottle. Everyone searches for the action card that "completes the story" begun with the first card. If a tweegle card shows scissors, for example, you need to find the cut-up tweegle among the face-up action cards. To claim the card, however, you need to perform the appropriate gesture: slapping the card if a mosquito is involved, hammering it with your fist if the tweegle was stamped, and so on. The first player to do this claims the tweegle card, while the action card remains on the table. Whoever claims the most cards wins!