Caine plays Jack Carter as an almost pure sociopath -- even his 'love' is really just a reason for violence, though he becomes vaguely sympathetic when contrasted to the mobsters he ends up fighting (mobsters just like the ones he works for, of course). It's a mostly soulless, shark-eyed performance, and one of Caine's very finest. This isn't the performance of an actor (or the film of a director) looking to charm the audience with rogue-ish gangsters and their wacky ways.
I'd call this movie kitchen-sink noir -- it's got the grimy, disintegrating backdrop and characters of the British kitchen-sink dramas of the 1960's and the murky, rotten moral landscape of all good noir. In some ways, the plot resembles the 1940's noir classic, Robert Mitchum vehicle Out of the Past. But the film world of Get Carter can show what a 1940's film noir can only imply.
There's no evident soul-searching on Carter's part as he uncovers the personal effects of the violent, impersonal world he's worked within for so long -- just ever-increasing violence that never provides the vicarious zing that a lot of violent revenge dramas do. There are simply men and women doing terrible things to terrible people and innocent people alike.
The sudden bursts of violence still have the power to chill 40 years after the picture's release -- Hollywood may have remade the movie in the oughts with Sylvester Stallone (!) in the Michael Caine role, but the movie's grim, anti-cathartic world isn't something a major studio would ever try to portray today. It would be too dark and too honest about violence. It would cut into the box office. Highly recommended.
