Classic mode, standard mode, journey mode, many levels beyond your imagination, pay tribute to the classic, but also some new ideas.
Revert operation when you made a mistake. The falling speed can be configured, so you can have a endless trip, the design definitely let you feel warm.
Simple operation, suitable for the old and young, it is a casual puzzle, a good way for killing time.
Wherever you are traveling, or in bed, have it with your hand.