Analze for me.

way to many pointless knight moves in the endgame. notice how the first thing your opponent did when the queens came off was move his king to the center of the board? also notice that from the center of the board he was easily able to keep your king pushed off to the side and unable to help your pawns.

Very well little Mr. Me! I like very much how you play the opening until  9.Bxe4?! i know at first sight it seems natural since the "disguised french" black Bishop seems a little bit arrested, the resulting e4 pawn is easily a target and once the e5 square is secured you can organize an advance of your center in order to push back the black pieces hopefully creating a passed pawn on 'd' file but... A second look revels that it only Increases black chances of counterplay since the d5 pawn slipped and the a8-h1 diagonal can be used quickly even losing the pawn if necessary, still the active black Queen discourages a bit the white castle kingside. For exemple: 9...dxe4 10.0-0 b6 11.f4 Qh6 (hitting f4, 11...exf3 12.Rxf3 is much worst) 12.Ng3 Ba6! 13.Rf2 e3 14.Rf3 Na5 seems to me a nice game for black.  

11.Bc1 Maybe your intention was to prevent the advance of the black pawn to e3 but the bishop was marvelous placed right there.

12.g3?   All he wanted more white squares for free! 

The rest has been said already.  Don't underestimate that knight sacrfice, the player with black proved a better positional understanding during the game. And i still dont think you are cool with 23.Qg2 after 22...Bb5.

Nice game buddy!! ; )