These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
And I Must Scream: Diabolik ends the film completely encased in gold, and apparently still alive.
Doesn't seem to bother him, though, considering the wink to the audience implies he actually thought this might happen and has a plan. That or the chilling laughter right afterward is meant to imply Diabolik has gone insane/finds probably being killed by gold ironic considering his extreme obsession with money.
Crowning Music of Awesome: An oddly spastic trumpeter is the only flaw in what is otherwise a terrific score by Ennio Morricone.
Designated Hero: Most people aren't aware from seeing the movie that Ginko is supposed to be the hero of the film, chiefly because he's constantly made out to be Diabolik's Chew Toy.
Magnificent Bastard: Probably the main appeal to the film is just how cool Diabolik and his methods are, even if they are evil and murderous. It contrasts nicely with Inspector Ginko being a Guile Hero.
Special Effects Failure: During the "skydiving" scene, one actor's leg goes partly transparent thanks to lousy compositing work.