Harry Brown review: Michael Caine's British thriller - watch trailer here

After we witness a naive gang member shoot a mother walking her child through the park (all filmed in 'happy-slapper cam' on a mobile phone, making it all the more disturbing), we cut to ex-marine Brown living his lonely existence in a run-down estate.

Out of his window he sees the local hooligans causing mayhem, yet he turns away, afraid, helpless to do anything. As an opening, it both grabs hold of you and efficiently paints a picture of a man trapped in his own home.

However, when both his wife and best friend die in the same week, Brown snaps and goes on a rampage against those responsible for his friend's murder.

Smartly, director Daniel Barber doesn't portray Brown as a straightforward good guy - he gives out retribution as cold-bloodedly as Caine did as Jack Carter some 38 years ago.

It's also admirable that the hoodies aren't initially black and white villains either. We are given hints as to why these troublesome youths are so troubled; one has a father in prison, while another, Marky, has a history of sexual abuse.

Yet, just when you think Barber has displayed his moral compass, he throws it to the floor and smashes it into tiny little pieces. Any sympathy we are made to feel towards these council estate criminals is quickly dispelled as each one is dispatched of in the harshest way possible.

It's as though Barber originally envisioned them as tragic products of their environment, but then thought 'oh to hell with it' and shot scenes like where Marky is blasted in the face in the most callous way imaginable.

There are times when violence can add something to a film, lending it a realism that is predominantly absent in the spate of bloodless Hollywood blockbusters we get these days. Yet here it feels like Barber is enjoying the bloodletting a little too much, causing the more 'talky' scenes to suffer. It's as though his work ethic on the film was getting the dialogue scenes out of the way so that he could get back to killing people.

It's because of this that much of the film feels like an exploitation flick mixed with a TV drama - in between all the time we spend with Emily Mortimer and Charlie Creed Miles, playing do-gooder cop characters which seem to have been lifted from The Bill, we have Brown slaying chavs in the most gruesome way possible.

And believe me, it gets very gruesome. One scene sees Caine impale a drug addict's hand onto a table with a knife. In another, we see an injured young crim with blood gushing from his freshly-shot neck.
It's all a very strange combination, a mixture of straightforward drama and gritty revenge fantasy.

What's most grim, though, is that the excellent cast is almost entirely wasted. 'This Is England's Joe Gilgun brings a heaping of sleaze to his drug-addled gangster, while Jack O' Connell displays genuine emotion in an under-written hoodlum role. Unfortunately, neither of them last very long. Similarly, the impeccable character actor Liam Cunningham spends much of the time behind a bar polishing glasses, waiting to say a line. Just when he finally gets to speak, Caine mopes out of shot, leaving Cunningham behind to wait for the climactic scene in which he briefly gets to show off his acting skills.

It's fortunate, then, that we spend most of the film's running time with the ever-brilliant Caine. If there's ever anything wrong with a Michael Caine film, there is a guarantee that at least one aspect of it will be good: Michael Caine.

A pensioner that lovingly dotes on his dying wife that by night gets revenge on neighbourhood gangsters by cold-bloodedly slaughtering them? It's a difficult role to pull off convincingly, yet Caine somehow manages it, remaining a towering presence throughout, see-sawing from teary, vulnerable old man to fuming harbinger of doom.

It's a rare thing to see a 76-year-old actor that still continues to improve with each performance.

Unfortunately, Sir Michael isn't quite enough to save 'Harry Brown'. The film often drags and could have done with an extensive editing session, while we spend far too much time in TV-police-drama-land with Mortimer and Creed-Miles' driven, by-the-book detectives striving to 'solve the case' when we already know everything.

Many critics have compared Harry Brown to Gran Torino - they're half-right. Although the two adhere to the same central story - a widowed man is driven to revenge when local thugs threaten his way of life - the central theme of the two couldn't be more different.

The message in Eastwood's film is to overcome prejudice and learn forgiveness. Harry Brown's message is one that mars most revenge flicks: violence equals justice.