The Four Pawns Attack is not particularly popular because many White players are reluctant to weaken the area surrounding their King or are wary of entering a sharp tactical line which Black may have prepared.
An interesting alternative is the ultra-sharp Planinc Variation, 5...g5!? where Black hopes for 6. fxg5? dxe5 which wrecks White's center and leaves him with weak pawns. Actually, about the only thing going for this line is the fact that White will have difficulty finding the best defense OTB.
In this game, instead of meekly retreating the N's in face of White's Q-side P rush, I boldly plunged them into his position, creating havoc against his K.