Celtic Mahjong is a timed tile-matching game that combines elements of the Celtic and Chinese cultures. In 10 levels, the player must quickly remove patterns of stacked tiles from unique locations. To compete on the global stage against other online players, they must also attempt to earn the highest score possible per level.
The player can start with the first level and pattern via the Play button or any level via the Level Select button. No matter the level they start in, the player performs the same steps to win. They must select matching pairs of tiles. In this case, the Chinese Mahjong ivory tiles display Celtic icons.
When the player selects the first tile in a pair, the game outlines it with red. After they select the second one, both tiles slide off the screen. They can only select highlighted white tiles that have one open side (i.e., right or left).
Celtic Mahjong also offers three powerful tools in the upper-right area to help the player remove all the tiles before time runs out. They can shuffle the stack to reveal pairs hidden under the top tiles, undo a move that restricted the selection of a new pair, or use a hint that makes a pair of tiles pulsate in place.
The right side of the screen also displays the score, level number and remaining time. The player can use the latter to motivate them and speed up their actions.