Nice.
I believe the reason behind black move no. 6. was
- He don't want to take the Knight as your Queen would be threatening his rook & he does not want to do f5 or Rg8 as he wants to castle.
- Can't move his Knight to e5 as f4 would force him to be back to square 1. Its the same case with Na6 or Nb4
- The reason he moved his knight was because he did not want double pawn (NxN NxN, BxN bxB) & then you can also attack his rook via Qd4 (reason applies again here)
Here is a game from a recent Team Match where my opponent did not develop his pieces well, and he was punished.