18...Qf2# -- oh yeah missed the comment.
In practical terms, against lower rated players, that fishing pole move catches a lot of fish... but in pure chess terms it's not a great move. I mean you can't assume your opponent is going to fall for it and take it. So if the N sac is declined you've got a N on g4 and you've pretty much committed to castling 0-0-0 or leaving your king in the middle. For what compensation? Is the N well-posted there? Not really... it ties your Queen and rook to it's defense. I think I'd play 9...Qb3 and see what kind of trouble I could stir up.
Last two games that I have played as black, ng4 has served me well in this kind of position. First one was a bit convoluted whereas this one was pretty clear.
Any comments welcome