Just like most Mahjong games, the aim here is to clear as many tiles from the board by selecting pairs of matching tiles. But in this game, it looks as if you only have five minutes to complete as many levels as you can, and attempt to beat your best points score. But ... look for the tiles which have "Time:100" on them - there are at least three pairs of these - but the time on them is counting down as you watch! Selecting these pairs ADDS this number of seconds to the time available; so play these as quickly as possible. Potentially, you could add 300 seconds to the time available as you start each level. To help you extend the time further, selecting the "Stop time" tiles stops time for 20 seconds; alternatively you can also "Slow down time". Note that the watch tiles all match each other, as do the stopwatch tiles.