2048

Move the boxes horizontally or vertically. Includes 4 horizontal and 4 vertical columns.
When two boxes with the same number and there are no box in the midle, you can merge them into one box with a total of 2 original box.
Begining 2+2=4, 4+4=8, 8+8=16, 16+16=32,...,512+512=1024, 1024+1024=2048.
When number 2048 are created, you are the winner.
Rules of the game are exceedingly simple, but you can train the brain to be active and develop your intelligence.