Game analysis #2 - The rules of attack and defence

GothicChessInventor asked for an analysis of the following game on the forums. As I found the game instructive, I decided to publish it here so hopefully other people can learn from it. 

The main points of the game:

1. White neglects the fight for the centre (9. Nc3 instead of 9. c4).

2. White wastes two moves to pick up a pawn when he is  already under a dangerous attack (14. Qg4 and 15. Qxg7). As a result, he ends up with a lost position. 

3. Black fails to bring more pieces in the attack to make it crushing; he rather moves the same attacking pieces again and again, until his advantage evaporates.