I don't read many comic books, but I read them like this: I skim very quickly through the book, and I admire at length the odd excellent picture. Then if it seems worth it, I go back to the start and read more thoroughly, to get the full plot. Some of the images in this film were like the excellent pictures which are worth dwelling on. But the rythm of a film is all wrong, the plot is too shallow for the time it takes to deliver, and you can't dwell for long enough on the good bits.
The film is very confrontational about two issues: gender and violence. Both are treated in a very showy, shallow, and unrealistic way. Because the characters are absurdly physically robust and don't go into shock the violence has to escalate to a level that is repetitive and depressing in order to have any impact. Because the female characters expose virtually all of their bodies the whole time their physical presence is (IMHO) diminished compared to women in real film noir.
The other problem for me is the gulf between the attractiveness of the male and female characters. All of the women are very sexy, in a narrow style of sexy, whereas all the men have been smashed repeatedly in the face with the ugly stick. The exception is Clive Owen, with the result that every time he is on shot it's like the Halleluja chorus. Elijah Wood plays Kevin, but as a malignant puppet, so attractiveness doesn't really enter into it.
Bruce Willis is also an attractive man, of course, but his physical presence is undermined by pairing him with a teenage girl. This increases the yuck factor to 11. I didn't hide my eyes when Willis shot the baddy's nuts off, but I had to look away when he snogged the teenager. (After saying 'but you are old enough to be my grand daughter' - yes, there's a clue there). It was utterly foul to see.
Undoubtedly this is a film that lots of people will like a lot. It was artistic, sporadically amusing, adventurous in its methods, and quite full-on. Some of the individual images were very good. To me that wasn't enough.