Formissimo

To set up the game, lay out 30 cards in a grid and give one card face down to each player. Each card has five attributes, with each attribute having two states: large/small, red/blue, square/circle, one/two items, and with/without cross. Someone shouts "Go!", then everyone looks at their card in hand. Players then start grabbing cards from the grid and stacking them in hand. The card grabbed must be identical to the top card in hand or differ from that top card in only one way. Thus, as you grab cards, the attributes of that top card will keep changing, forcing you to look for matches in new ways.

Once a player thinks he can't grab any more cards, he yells "Stop!". The round ends, and all players check their card stacks. If someone made a mistake when grabbing cards, that player keeps none of the cards gathered that round. If the player who stopped the round made no mistakes, he earns an extra card. If, however, he stopped the round when he could have collected more cards, then he loses all the cards he's collected during this round.

Whoever has collected the most cards when the game ends wins!