Solving: Proof Game (fantastic!) after 12 moves

You might wonder or solving different kind of puzzle like (Helpmate, Selfmate, Proof Game, Study, Mate in 2, 3..) is really helpful in chess?

In my Opinion the Answer is YES because chess is creative game not just about learning Opening Theory, Endgame and so on.. The most important is Middle game where you must often alone to find a Plan, miracle Defence, Attack, or just make nice Mate or Puzzle. Solving is close related to chess, so I'm sure that sometimes for fun solving this kind of off-beat puzzle is very creative and helps develop imaginative thinking and to train our Brain.

Let's start with only one really fantastic proof game. It doesn't matter or you are just Beginner or Grand Master. Everybody can solve this puzzle but it's really really tricky!

I was taking part in Chessbase Christmas Puzzle 2011 (Presenting by GM John Nunn) and that "Proof Game" was for me the most fascinating to solve. I solved this building this slowly step by step. 

And If you solve this you are really superb  You can use Computer to check Your Solution..

A proof game - is a type of retrograde analysis chess problem. The solver must construct a game starting from the initial chess position, which ends with a given position (thus proving that that position is reachable) after a specified number of moves

Please set up this position on Your Set and think at least one Day!! I'm Not joking  

Remember that the all moves must must be legal like in normal game! So you must reproduce this game since beginning till last 12.. Black Move

There is only one Solution