It is a classic Mahjong solitaire with 3D cubes. As in the original game, which is made for the real world, in this virtual version players have to remove all the pieces from a group, taking pairs of identical. Some of them are blocked by other cubes, and the game will not allow taking them – click or tap those, which have at least two free sides. The time of this free mini game is limited, so it is better to act quickly. How many points will you get for 6 minutes? Every cleared stage adds 10 seconds to the starter time.
A similar gameplay may be found in matching puzzles, where players look for identical objects and make lines of three or more of them. For a try, play Mix & ChristMatch on the Very Good Games blog!