I like how that one is so much more realistic than the still undefeated 8 knight promotions puzzle. It looks like a blitz game where white tried to ram the queenside with everything but got careless and let that e pawn through, or mouseslipped and forgot to to move the king to f1, but still managed to pull an obscure mate out of it lol
Here's one similar to the 8 Knight underpromotions, but with only 7.
White to move and mate in 7:
I feel like that one could be modified to have more pawns and end up having multiple knight underpromotions similar to my previous one like this:
Even better.
Yeah starting it with a queen sacrifice as the only winning move and then multiple underpromotions is even better. Those cascade-underpromotions are cool.