Material does not matter !!!

Yes if black always plays soooo goood that it comes under such a neat position. . . . . To get checkmated!

White to play and win (actually mate in 16).

Nope. It's a regular puzzle- both sides play normal moves, and are doing their best.

To me it looks like mate in 8. I guess I'm missing something.

How can you even come close to mate in eight?

For the record, the diagram is regular (the board is not reversed), although I guess that with board reversed white is completely lost.

In response to post 3:

1.Kxe1 (otherwise the Knight moves and Black wins) Qa1 2.h3 (Knights can't lose a tempo, and he must mate on a light square, so Queen needs to be on a1 when that happens, similar to the WKa8, WPa7, WNh1, BKd8, Black to move and draw problem) Qa2 3.h4 Qa1 4.h5 Qa2 5.h6 Qa1 6.h7 Qa2 7.h8=N Qa1 8.Nf7 Qa2 9.Nd8 (9.Nd6 Qa1 10.Nxc4?? Qa2 11.Na5 c4!! 12.Nxc4 Qa1 13.Na5 Qa2 and White has no win) Qa1 10.Ne6 Qa2 11.Nxc5 Qa1 12.Nb7 (there are other options here) Qa2 13.Na5 Qa1 14.Nxc4 Qa2 15.Na5 Qa1 16.Nxb3#

Here's the Black to move and draw I was referring to.  1...Kc8 draws, 1...Kc7 loses.  Move the Knight to g1 instead of h1, and 1...Kc7 draws, 1...Kc8 loses.  Rule of thumb for that position is that you must put the King on the same color square the Knight currently resides on.  In essence, you want White to be able to check you.  What must not be allowed is that White covers the square you don't occupy, then you are in Zugzwang and White wins.  You might think this can't happen, but it can in a real game (and has once in my case).  Usually it's Knight and Pawn vs Minor Piece scenarios, where Black sacrifices his Knight or Bishop on a8 if the pawn is on a7, and his King hems in the White King, but he has to do it on the correct square!

I missed that d2 is covered and planned to mate with a Q there.