True. Maybe better: 3 diagonals+, 1 diagonal#
Anyway, nice one :)
4 diagonals
Sort:
Easy.
White dreadfully punished! Easy one.
Wait! This thread is 3 years old! NewArdweaden bumped it.
NA, I tried every white's move, but nothing was correct. And you say "Easy". 
MA10, not sure why he bumped it. Surely I must have been black in this game and he was white, so... 
This is my game, where I missed a simple checkmate in 4! :)