False advertising. The puzzles never get hard, the statistical probability of you losing them just increases. As you pass levels more cards are added meaning more things to match in game. By level 100 you have about 8 or 10 cards that all require pairs of three to disapear. For each level the placement of the cards becomes randomized meaning that you could never get a single match in game. Then cards start to be stacked on top of eachother meaning you don't even see them. Awful game design.