Seven checkmates
The core idea of the - unacceptable - offer 16. - Ng4!? was just occupying the long black diagonal after a subsequent Ng4-e5, Nf3xe5, Bf4xe5, however its - wrongful - acceptance gave way to some lines ending in nice checkmates (labeled A-G).
Some of these checkmate lines are not forcing, or at least not in that move count; often White could sac his Queen or other material to prevent the worst or at least prolong the game, but I skipped those lines for brevity sake.
So this is not meant as a complete analysis but just a collection of some attractive, and partly unusual, checkmates.
My personal favorite is the one labeled "E"; the one after the possible double check in the 19. - exf4 Nf3++ line.
