Seven Psychopaths is an incredibly meta film, which is part of its appeal.
How meta is it? It's a film about a screen writer who wants to write a film called 7 psychopaths. And that's just the beginning.
While the storyline seems bland on paper; filmwriter trying to write a film about 7 psychopaths mixed in with dog kidnapping and a crazy gangster trying to find his shih tzu, it's the humor that sells the film. In a style reminiscent of older films like Get Shorty or Kiss kiss bang bang, there's an overlaying plot that ties in many smaller subplots into one crazy, humorous film.
Throughout the film, the characters make many self-referential quips about the film, ranging from the writer saying he didn't want the film to be just about violence and wanted it to be life-affirming in a way and how the characters in the film should just go camp out and talk (which they end up doing btw), to one of the psychopaths saying 'hell no, the film should end in a gunfight'; looking directly at the camera as he says so.
It's not just the meta-humor that makes the film an enjoyable watch. The actors all give stellar performances in the film as well, managing to deliver the lines with the right amount of dry sarcasm and snark.
Overall, I'd say this film was worth watching although it's probably not running in any cinemas anymore but I'd recommend getting a DVD or blu-ray of the film to watch.