Black's last move seems to be Kg3-h2, and white's last move seems to be Bxf2+.
Black's b pawn promoted on a1 by capturing the only white piece available for capture - a rook, and h pawn promoted on h1.
In order for white to have two dark-square bishop promotions, his e pawn must have promoted on d8/f8, and h pawn on h8 (more efficient than d8/f8) for a total of 3 captures. Black's e pawn in this scenario seems to be useless to me. That leaves black with 1 extra piece (dark-square bishop, rook or queen) to be captured later on f2.
Other than that I cannot see any difficulties at the moment - alas I do not have time to make a proof game. Perhaps someone else can, or find a flaw in my analysis.
It's like two weeks ago that I've been posting anything but I made another one, there are still problems open, because I do want an analyses/game. Here's my new one: