I'm not very good, and this game is against the default WinBoard engine. Analysis would be greatly apreciated.

You should have played 20. Nd1 to save your knight. I think that 22. Qxd6!? would have given you some counter-chances.

Instead of 23. g3??, you should have played 23. Rxf4, which gives you some chances. After that, you could have simply resigned. 

For some reason I wasn't thinking about moving the knight, just its defenders(Move 20).  In the annotation, I think I stated that I missed the pawn, but g3 was a bad move nonetheless (Move 23). I didn't really want to resign, as I just wanted to see how the game played out.

hmmmm... im no expert either, but since my opinion will be 'greatly appreciated'...

i like ur opening, it was nice and bold with both your knights and bishops covering much of the board.

however, towards the middlegame, u started making mistakes, which eventually gave the game away.

but u still played well :-)

Thanks

8. Nxc6. I don't like this move. When black plays 7. ... e5 he gives up control of the d5 square, the exchange of knights lets black bring a pawn to c6, regaining control of the d5 square.

 

10. b3. I think there are more active ways to play here. You have a lead in development, so you want to break open the position and take advantage of your opponent's poor placement of the pieces. 10. f4! and if black wastes time going after the b-pawn 10. ... Rxb2 11. fxe5 dxe5 Your rook is unleashed on the f-file. You can immediately win your pawn back with 12. Qxd8 Kxd8 13. Rxf7. I much prefer white in this position.