2048 is a remarkably simple and addictive game

As complex as Rubik's cube but as simple as the Number 15 Puzzle.

http://gabrielecirulli.github.io/2048/

Wish I had thought of it first.

On the PC you press one of the arrow keys to move all the tiles in one
of four directions. On my smart phone I was simply swiping instead.
The object is to combine numbers that have the same value You win
the game by getting one of the numbers to 2048, which seems nearly
impossible before the board fills up with new numbers and you run out
of moves.

The game seems really addicting. BTW, I have had the powers of 2
memorized since like 5th grade , so this game was especially appealing
to me.