You could try to solve it, but it may be more fun just to play through the answer.
The idea is that White's last move will be Qxe2+, with Black forced to reply Nxe2 mate; and that can work only if the squares round the white king are blocked by the appropriate pieces.
So here goes: 1.e8=N, 2.Nxf6, 3.Nd5, 4.f6, 5.f7, 6.f8=Q, 7.Qxf3, 8.Qg2 (lying in wait), 9.f4, 10.f5, 11.f6, 12.f7, 13.f8=B, 14.Bxh6, 15.Be3, 16.h6, 17.h7, 18.h8=R, 19.Rxh4, 20.Re4, 21.h4, 22.h5, 23.h6, 24.h7, 25.h8=Q, 26.Qxb8, 27.Qe5, 28.b8=B, 29.Bxa7, 30.Bc5, 31.a7, 32.a8=R, 33.Rxa4, 34.Rb4, 35.a4, 36.a5, 37.a6, 38.a7, 39.a8=N, 40.Nb6, 41.Nc4, 42.Qxe2+ and Black must play Nxe2 mate.
White has promoted all eight pawns, two to each type of piece. An extraordinary composition.Reuse content