2x2

1.b2-c3 g7-f6 2.e1-d2 f6-e5 3.d2-e3 e5-d4

[ 
or 
3...c5-d4 
4.e3:c5 
e5-f4 
5.c5-d6 
f4-g3 
6.d6-c7 
g3-f2 
] 

4.c3:e5 c5-b4 5.e5-f6 b4-c3 6.f6-g7 c3-b2 1-1