The pin is mightier than the sword

I played a game earlier today, which was quite strange in many ways. Both players made several mistakes, and the game was quite even. That is until my opponent decided to open up the position and let me create pins everywhere. The game ended with a strange blunder which I simply cannot wrap my head around. I guess my opponent must have become tired from calculation and just lost focus completely.

The game progressed in the same manner as it did. Whatever advantage any player could have had was thrown out the window. At this point in the game, I came up with an intriguing idea which I did not execute.

The end of the game was quite interesting. Not because it was so exciting, but since the position was so full of tension and pins. I have an unprotected piece, but black cannot take it because the bishop is pinned to the queen. In addition, the knight is pinned to the queen and to the g7 square/pawn. A good demonstration of how powerful a pin can be in a game.