One person it chosen as ‘it’, and the remaining players spread themselves standing about the room. The chosen person is the only player allowed to smile, and it is their task to make as many of the others smile as possible. They can do anything they like to induce a smile, short of touching the other players (no tickling allowed!)
You can play the game so that when a person is made to smile, they are out and must sit down, and the last player left standing is the winner. Alternatively when the chosen person makes another player smile, they can swap places so the smiler becomes the smile-inducer and the game can continue indefinitely.