This is an early Fassbinder film, and from what I've seen, one of the best of his first 11 (which make up his first stage as a filmmaker). It's Fassbinder in gangster mode, and has been called an homage to film noir or even a parody of film noir. This isn't the case though. The movie is just film noir done by Fassbinder. There are little homages here and there, the beginning and end could be seen as being inspired by Breathless (taken to ridiculous extremes), and there are lots of filmmakers names used as characters, but Fassbinder isn't winking at the camera so much as just being himself, which back then, could be quite bizarre. In fact, this might be one of Fassbinder's most bizarre movies.
The camera stands still, characters occasionally deliver seemingly unrelated monologues, unusual plot lines are treated nonchalantly (Ricky's brother is in love with him?), people about to be killed don't seem to be worried, and the singlehandedly greatest song ever plays over and over again, crooning "so much tenderness is in my head, so much loneliness in my bed." To have this song play over scenes of a stone-cold amoral hitman (the title character) casually driving his car are perversely hilarious. Even better is when it plays in the end, in one of the greatest endings I've ever seen (you'll have to check it out).
The recent release of this film on DVD should help bring it some attention, as its now available for a pretty reasonable price from Wellspring. If you're looking for one of Fassbinder's more mature, professional, socially poignant melodramas, maybe this isn't the movie for you. If you're interested in an extremely unique unclassifiable early Fassbinder, by all means, check this out. Despite the occasional nods to past filmmakers, it's surprising how unique Fassbinder was from the start.
(for those who are Jim Jarmusch fans, it's apparent films like these must have inspired the detached humor in some of his more recent films).