We Spot! is a game where you try to match symbols between cards. The symbols are randomly placed and rotated on the cards, and then the deck is shuffled.
The symbols and cards are designed so that any two cards will contain one, and only one, common symbol. The trick is to find that match as quickly as possible. It's not as easy as it sounds.
The number of cards in each deck is mathematically related to the number of symbols on each card. The more symbols, the more cards, and the harder it is to find the match.