This is a Japanese press-your-luck game based on characters created by Finnish children's author, Tove Jansson. Each player is trying to collect the most Hattifatteners, mysterious, ghost-like creatures who grow out of the ground and are attracted to electricity.
The deck in the middle of the play area represents the mountain the Hattifatteners congregate toward, drawn by the lightning at the top. Each player begins with three plastic Hattifatteners. On their turn, each player will draw cards until they meet one of three conditions:
1) Collect 12 Hattifatteners represented on Nyoro Nyoro cards.
2) Draw a Biri-Biri card, causing them to discard all cards in their play area.
3) Choose to stop drawing, and pass to the next player.
Some cards allow you to take Hattifatteners from the field, or from other players; some cards cause you to lose Hattifatteners to the field. When the draw deck is exhausted, the player with the most Hattifatteners wins.