(M) ***

Director: Angelina Jolie.

Cast: Jack O'Connell, Takamasa Ishihara, Domhnall Gleeson, Garrett Hedlund, Jai Courtney.

WAR is hell, but few soldiers endured as much purgatory and perdition as Louis Zamperini.

As such, his story is a compelling one that shows just how much the human spirit and body can endure.

Unfortunately this tale of survival has little else to offer beyond its tale of survival.

It begins with Zamperini's time in the US Air Force during WWII, dipping in and out of bombing raids to recall his pre-war life in Torrance, California, as a troubled kid who turns his life around and becomes an Olympic runner.

But one fateful mission over the Pacific Ocean indirectly lands Zamperini in a prisoner of war camp, with the experiences that follow best likened to Dante's Inferno and its many layers of hell.

Largely unknown English actor O'Connell gives a breakout performance as the ill-fated runner/soldier, effectively portraying the pain, stoicism and large emotional range the role requires.

But it's certainly no fault of O'Connell's that we don't get a clear understanding of what made Zamperini tick.

That fault lies with the script, which so focused on its events that it forgets to give us much in the way of characters.

As a result, Zamperini is portrayed as little more than "the guy that survived" - we get no sense of what he was like as a man beyond the fact that his spirit was "unbreakable" and that he was a fairly decent guy. We are left with no idea about what really drove him and kept him going through such horrific experiences, and even less of an idea about his fellow POWs, whose names we barely even get to know.

Because of this it's a while before we gain any real empathy or context for characters, despite them enduring some terrible things.

An audience is always going to care more about people if they get to know them, but there is little in the way of introductions or development for these POWs. It's really only the relentless weight of their suffering that allows the film to break through emotionally, and as such it feels like Unbroken sells its subjects short.

This is certainly no fault of the cast, who acquit themselves well, especially O'Connell but also Ishihara as POW camp commander Mutsuhiro "Bird" Watanabe, who conveys the right amount of repulsiveness in his turn.

It's hard to fault Jolie's direction too much either. The film takes a little while to get going but moves at a decent pace in its latter half. She also avoids making the necessary violence far from gratuitous, while Roger Deakins' cinematography (which has earnt him an Oscar nomination) gives the film a classy look.

The problem lies with the script and its "events, not characters" approach.

The film is not filled with scintillating dialogue or amazing set pieces - although the opening aerial dog fight is pretty cool and the Olympic sequence is done well - so without character depth to drive the necessary emotional punch we are left with little more beyond an hour of hardship.

The film is certainly worth a look as it's a compelling story, but you will walk away knowing what happened to Zamperini and not who Zamperini really was.