Mahjong Peng is a tile-matching game based on Mahjong. The player must select and remove pairs of matching tiles attached to a hanging banner that serves as the playfield. The game doesn't feature tiles layered in different patterns, like with classic Mahjong. Additionally, the player doesn't only select tiles to make a match. Instead, they must deal with sliding-tile mechanics.
The player starts out by selecting the Easy, Special or Normal play mode. They then select any matching pairs of tiles that rest side by side on the field. The game uses classic Mahjong tiles that display red and blue bamboo sticks, stones and dragons. When the player selects a side-by-side pair, the tiles flip over. When no more of these options remain, the player must then slide one or more tiles into a position that aligns at least one tile vertically or horizontally with its match. The matching tiles only flip over if they're already linked to flipped tiles.
The game displays a guiding hand that shows the player matching tiles and the correct method to use to align tiles. It also highlights free tiles available for a match with yellow highlighting.
The player wins Mahjong Peng if they flip all the tiles on the field.