I'm not trying to make a 'memory game' but the logic is the same.
The game has 4 (picture) sprites: pv1, pv2, pv3, pv4, and a card sprite that covers each of them.
1, The player clicks on a card the opacity is set at 10%, revealing the 'picture sprite' below.
2, The player clicks on another card the opacity is set at 10%, revealing the'picture sprite' below.
3, If the 'pictures sprites' match, the cards and 'picture sprites' are destroyed and the player gets a match.
4, If the 'picture sprites' dont match, the cards reset, and the player tries again.
5, Once the player achieves the required number of matches, the player enters the next stage.
Iv'e seen various posts with solutions to this, but each one had about 100 seperate event's.