1.Nf3 f6 2.Nd4 Nh6 3.Nf5 Nxf5 4.d4

Black can try:

4...e6 5.Nc3 Bb4 6.e4 h5 7.f4 d5,

4...c6 5.Nc3 d5 6.e4 b5 7.h3 h5.