I know many flaws are probably due to the basis being from the 60s but this was mainly a letdown.
The exposition took way too long for the characters being so unimaginative and onedimensional. From protagonists to antagonists really everyone was a trope blueprint. The story was rather boring and really worn out.
The twist within a twist was somethings worth mentioning, the first one even unexpected to me but I just didn't care at all for the betrayal.
Usually I like Guy Ritchie movies a lot but this one was lacking so many elements that make them great. The ones it had, like the comic panels, made the movie more enjoyable but there was definitely lacking a lot!
Where the movie failed the most in my opinion was the buddy dynamic. It was suggested but delivered on so little that I sometimes really wondered what this movie wanted to be.
And why can they cast two Germans but when it comes to the female lead who is also supposed to be German they cast a Swedish and all her German lines sound awful. Same for most of the Italian... aren't we past that by now?

Really the only things enjoyable were first the setting, sets and locations and costume. It looked authentically like the 60s in those places. And second the editing of the action sequences.