Black plays rather conventionally, overlooking some interesting active possibilities such as 11...Qa5 which would have thrown White off his game, but is not in any real trouble until he gets lazy on move 17. Centralizing the knight looks good for all of one move, then White's pawns immediately start rolling over Black's pieces, punishing him for lack of attention. Black misses a rather complicated defensive idea and then is down a full piece, putting up staunch resistance in the endgame but to no avail.
I got the most positive value from analyzing this game from looking at the piece exchanges resulting from the opening, which look OK for Black, and understanding how moves like 11...Qa5 can be advantageous. The negative lesson is rather obvious, since Black failed to falsify his move, which would not have been very difficult to do (i.e. simply seeing the move 18. c4! from his opponent, hitting the Nd5.) It's interesting to see how easy it is to pick out thought process mistakes in game analysis, which leads in turn to a significant part of the improvement process, that of recognizing and correcting recurring mistakes in play.