The guy on the cover image is a hired killer. The film opens with quite a long take of him smoking on his bed. That didn't really set the mood for the film either, but initially tells you, this film is either going to be boring, or have style. I thought it might be a French Get Carter, but it wasn't. That's where "minimal" comes into it.
I could name drop a lot of films that have been inspired by this film. The film looks at a lone wolf character. The guy doesn't say very much, but carries the character superbly. Without realising, you would feel that anything you've seen before in "gangster" films was done here first. This is about as authentic as a gangster film gets. It's the opposite of Goodfellas and co. Quiet young guy, doesn't have any friends, isn't using profanity for punctuation, isn't drinking copious amounts of alcohol.. He's wearing a hat and a raincoat.
Throughout the film, he's not actually getting away with crime and G'ing it up. He has the cops and other people after him. One review even called this "existential". You'll see why at the end scene. I wasn't expecting anything profound from this at all. That is pushing it though -- who can relate to a hired killer? Hardly insightful. I bet a reviewer has said something about us all being able to relate to him because our society pays us for our survival, etc, etc.
To conclude, a very stylish, influential film that instead of concentrating of portraying greed and the luxury lifestyle of a criminal shows us a lonely guy living in a one bedroom apartment, with a budgie, and manages to do all of the former in as few words as possible.