4 moves

See four!

(c4)

OH dang i read it wrong, i tought in atomic.

i have this one with the same idea
lichess.org/editor/rnbqkbnr/pp1p1ppp/2p1p3/8/8/8/PPPPPPPP/R1BQKBNR (4moves)

and this funny one in 10 moves
lichess.org/editor/nrbqkbrn/pppppppp/8/8/8/8/PPPPPPPP/NRBQKBRN

@classicalMpk
the second one is easy.
1. Ng3 Ng6 2. Nb3 Nb6 3. Nd4 Nd5 4. Nf3 Nf6
5. Ra1 Ra8 6. Rh1 Rh8 7. Ne4 Ne5 8. Nc3 Nc6
9. Nb1 Nb8 10. Ng1 Ng8