DO NOT play 1.f4 unless you have an answer ready for From's Gambit, 1...e5!? King's Gambiteers can happily play 2.e4. The line White played in the game was fine up to a point. IM Tim Taylor in his book
Bird's Opening recommends 7.d4 Ng6 8.Nxg6 hxg6 9.Qd3! Nc6 10.c3! Bf5 11.e4 Qe7 12.Bg2 0-0-0 13.Be3 Bd7 14.Bf2!, when Black doesn't have enough compensation for the gambit pawn. Another line is 5.d4 g4 6.Ne5!, heading into a slightly better ending for White after 6...Bxe5 7.dxe5 Qxd1+ 8.Kxd1. Instead of playing these reasonable lines, most of my blitz opponents have played ridiculously and gotten crushed. A case in point: