Actually, black can play ...Nxh8, but White still wins after Qe2+.

you be wrong: 1.cxd8=Q+ Nxd8 2.exd8=Q+ Kxd8 3.gxh8=Q changes everything.

Interesting that white has the standard complement of pieces while black has 3 queens - I assume from advancing pawns. I'll say that despite being bottled up in the back, black has more advanced queens and knights, so I think that black has the advantage