Fire and Water Stickman
Mahjongg Solitaire offers a matching challenge. Also i find it relaxing to match pairs of tiles to clear the board.
Match pairs of tiles to clear the board, and play Fast to complete the level.
The main mechanic is clicking on matching pairs of tiles to eliminate them from the board. A timer is stated to be present in some versions.
Watch for tiles that are not blocked by others. Prioritize clicking on unblocked matching pairs to increase your chances of clearing the board.