Chess puzzle help

Hi, I am struggling with this chess puzzle from Advent of Chess, Day 7. Can someone help me?

Give a sequence of moves that ends in this position after White's 6th move (when you reach this position, White moved last). 

Hm I can only solve it in 7 move

I know I’ve been trying to figure out the solution for quite some time... The puzzle is from Advent of Chess day 7. Perhaps it’ll help that from black pieces only the knight on g8 will move and whites sixth move will be taking that knight on a1, c1, d1, e1 or g1. Please let me know what you found.

This is in seven moves:

Thanks. I already got the answer:

1. d4 Nh6 2. Nd2 Nf5 3. Ndf3 Nxd4 4. Kd2 Nxc2 5. Ne1 Nxe1 6. Kxe1

(Advent of Chess, Day 7, Offerspill)

Nice solution!