The objective of the game is to put number in order like this:
                
                    1   2   3   4
                    5   6   7   8
                    9  10 11 12
                   13 14 15  -
 
Click  a number around the empty house (but not in diagonal) and the number slows down to the select house.
 
It's a puzzle: be patient and persevering, sometimes is not easy finish the game... Here is the interesting thing!