I think there are more pawns than is possible....
White to play and win
I guess so lol.... Just ignore the fact, and treat it as a fantasy puzzle. I hope apart from the fact there are two many pawns, my solution is ok.
My first try was Nd6 with the same theme in mind, but I think this allows black to get back into a stalemate position one move too soon (which I suppose could be alleviated by sacrificing the other knight).
Promoting to a queen followed by Qa8, Qa5# would also work here.
Putting a white squared bishop for white on a8 gets rid of the alternate promotion solution (as it would require one more move to get around with a Queen thus allowing 6...gxf1+).
I initially thought that 2. Ne5 might be an alternate line that worked as well, but it too allows black to get back into a stalemate position too quickly with exd4 (where sacrificing the f1 Knight to continue play is unthinkable).
I think that this single change (the addition of the bishop) resolves this puzzle down to having only one solution.
I have to say that I like the theme.
Try to solve and let me know what you think