Treasure of the Dragons

From BoardGameGeek:

Treasure of the Dragons - first released as Schatz der Drachen - is a memory variant for children. The goal is to collect as many of the 49 cards as possible. At the start, the cards are laid facedown on the table in a 7x7 grid. On their turn, players may reveal as many cards as they like until either they want to stop or they are forced to stop. If they stop voluntary, they may collect sets of cards: jewels or dragons can stand alone, but to collect cards with a treasure chest, one needs to have four of them. A revealed spider stops the player from taking anything. A revealed dragon also stops a player, but only if they have also revealed other types of cards (like treasure chests). At the end of a turn, a player flips all cards not collected facedown again. The game ends when all cards (except the spiders) have been collected. The player with most cards wins.