When I was watching this film I thought that it was older. The music, the story, etc… Frank is the maniac from the title and we see things literally through his eyes. Frank repairs mannequins and has some psychological problems that he goes somewhat too far to get the assessoires he needs.
The approach reminds a bit too much of “Dexter”, but “Maniac” is much more a horror and certainly darker. The atmosphere is alright, so it was not such a bad film.