Black's moves are natural and good.
1. g1f3  1... g8f6  2. g2g3  2... c7c5  3. f1g2  3... b8c6  4. d2d4 This move is not a good attempt to gain an advantage. 4... c5d4  5. f3d4  5... h7h5 What a curious move! Out of nowhere Black decides to advance the h-pawn instead of developing the pieces. Of course this is an exotic move and not the most popular in this position. In fact, it's only the seventh most played, quite a feat considering that Black doesn't have many moves available. The idea is to get the pawn to h4, but should White worry about that? 6. h2h3 To me, advancing the h-pawn, whether to h3 or h4, is losing the psychological battle, if such a thing exists. I think White should be fearless and choose 6.c4 or 6.Nc3. 6... e7e5  7. d4b5 This is a new move in this position and it is no exaggeration to say that it's already a losing mistake. 7... d7d5  8. g2d5 This move is the only justification for white's previous play, but black's initiative is devastating now. 8... d8a5  9. b1c3  9... f6d5  10. d1d5 