We have heard a lot about the game 2048: for example that Gabriele Cirulli, who suggested it in open source, got inspired from already existing products (which he declares openly); then that there are similar games, strategically better and so on.
Whoever wishes to know more about it can find information on Wikipedia.
Well, 2048 is very popular, a lot of people have played it and love it.
I played it too, having a lot of fun and even a light feeling of "addiction" to it.
The game goes on with multiple numbers of 2: the grid, by each move, shows another 2 (in an unpredictible position) and sometimes  a 4. When two identical numbers touch each other they sum together. For example two 2s become a 4 (22); two 4s become a 8 (23); two 8s become a 16 (24) and so on until the goal of the game which is 2048 (211).
I reached 2048 imediately, and I found the game rather easy. So I went on reaching 4096 (212) and then also 8192 (213).
At this point the game became challenging: until where could I arrive?
With such high numbers there was another kind of frustration: a 2 that compared in the wrong place was going to ruin an hour of "work", or a wrong touch of the screen on the smartphone was sending the numbers to the undesired side.
How to reach the theorical limits? And what are these limits?
A first answer could be 216 (65536), since the squares are 16; one could fill in all the squares with the powers of 2, so 2 in the first square, then 4 in the second, then 8, 16, 32... until 65536.
Almost impossible.
But then I found a version on internet with the function "undo", so you can go back to the previous move: you simply cancel the move and to it again.
Uhm... in that way I guess one could reach the theorical limits! But what a long work!
And then, at that point, could one go even further? Oh yes, becuase, if in the last square instead of a 2 you get a 4 you can move on on all the 16 squares reaching 217, which would be 131072!
This was a big challange and I wanted to reach this goal. Even having the "undo" function I had to front very difficult passages... I loved this challange. I had  a month doing it, with something like 150.000 touches on the screen (considering one second for each touch it would be more than 40 hours). But at the end I reached my goal! I don't know who tryed this crazy feat, but once I reached the top I got a little sense of abstinence... what to do now?
So, here below the print screen of my result.
Ok, ok, don't put me in a mental hospital... I won't do it again!
I only cared about the final configuration and not about the score, then I realized that it would have been possible to have a little bit higher score, caring not to use any 4s during the game, except the 16 which really are necessary to complete the game.
Anyway I read someone claiming the "world record" with a score lower than mine (which, btw, was 3.885.680).