The only complications I found in Sin City were keeping up with the rambling voice-over from Marv, which was (as in all of Miller's graphic novels--which is a more 'mature' term for COMIC BOOK) an obvious and derivative spin-off of Chandler.
The only character arcs in this film are from living to dead. The only narrative twists in this film are the ridiculous ones at which I laughed (because they were actually funny, and I think intentionally so): when Marv, for instance, lived through the first dosage of electricity in the chair.
"Is that the best you can do, punks?"
Mick