Pair
3 games
Description
Finding a pair is such a simple instruction that a game built on it lives entirely on what it puts in the way - a path rule, a layered stack, a board that shifts.
Crystal Connect adds a path restriction, so seeing the pair is only half of it and joining them is where the puzzle actually lives. Mahjong Christmas Holiday and KrisMas Mahjong 2 use the layered mahjong stack, where taking the wrong pair first buries the tiles you'll need later on. They'll let you take as long as you like over a move, which is just as well because the restriction is what makes them hard.
There are 3 free games under this tag, all playable in the browser with nothing to install, and they'll all let you take as long as you like over a move.
The wider mechanic is Matching games, and Tiles games collects everything played on a board of them.