Gilmoy: <10..e6> is a French pawn structure. How does White attack a French? Not easily: the lesson of centuries is that the French is oddly resistant to caveman tactics. In particular, the Qd2-Bf4 (or the more usual Be3) Yugoslav Attack formation finds almost no targets. Actually, it's White's QB that has no diagonals, hemmed in by his own e5. So White's "piece advantage" isn't helping him yet.f4-f5 might pry open the K-side. <11.g4 12.Bg3 13.Rdf1 15.Ne1> laboriously prepare for that. See, White's pieces are actually so bad that he must <undevelop> two of them just to get them out of his own way.
Meanwhile, White's long-castling invites thematic Q-side storming with <15..b4>. Positionally, Black's mobile pawn mass suggests Tetris: White really should have a clear (and quick!) plan on the K-side to counteract that.
<11..Nd7> is surprisingly flexible (which underlies Black's opening idea): with <12..Bf8> it threatens c5 if Black needs it, or dynamically reroutes to <16..Nc4>. White's final fault was hanging d4: he stubbornly(?) clings to the idea that he's in a left/right race, where you elegantly drop material on one side for tempi to crash through on the other. But he's so far behind in that race that his f2 is still on f2.
Black sees the obvious N-for-PPP trade: materially it's fine. It does give White a 5-to-1 "developed pieces" lead. Actually this hurts White: open d and lack of K safety means he's got too few squares for too many pieces. It's picturesque that his K dies on f3: blocking f2 and Rf1. That's nature's way of telling you that your f5-plan is <really> too slow.
sac: 18...Qxd4
