Pirc Player Underestimates Simple Attack

Here in my latest club game against Bourne End, my opponent chose to play the Pirc again 1.e4. I seem to remember seeing some games against the Kings Indian recently where White can have their pawns placed aggresively on d4, e4 and f4. I think that this setup is known as the 'Austrian Attack'? I elected to play this setup, given that I think that the f pawn should not in any way be obsrtucted by the Knight on f3. I have used the 'Saemisch' variation in the past (for White) with limited success, learning it because my old chess mentor, Adam Sobey used to thrash me with the Kings Indian as Black every week! I guess I learned from my mistakes, but I was expecting much more of a Queenside attack from Black in this game! After the King moves on move 20, fxg6 is coming, with the possibility of Knight jumping to h5 for backup ...