Cards lie face down in a grid. Tap two to turn them over: twins stay open, other pairs turn back after a moment. Clear the board to finish the level and earn up to three stars for few misses. You have three hearts, and a heart is lost only when you miss a pair whose twin you had already seen. The first levels start with a quick peek at every card; boards grow from 2 by 3 to 6 by 6, and from level 7 some levels shuffle the face-down cards after every few misses.