The opening moments of After Earth hurtle into life with such frantic energy and force it is like its own trailer. With little more than a close-up of a boy and a man and some sound effects, M. Night Shyamalam conjures up a gripping start for his latest tale.

Despite a spectacular career cascade that has seen him go from The Sixth Sense to The Last Airbender in little more than a decade, there is still evidence that the director has still got it; he just doesn't know what to do with it.

This sci-fi drama is fundamentally a Smith family home movie.

One thousand years after humanity has abandoned it to live in the stars, a spaceship crash lands on Earth. The two survivors are a stern military hero (Will Smith) and his (real life) son Jaden, an earnest cadet who excels in training but turns to jelly in the face of danger. With his father suffering a broken leg Jaden has to embark on a treacherous mission to secure a rescue beacon from another part of the ship's debris.

There is the seed here for a neat comic twist on the standard sci-fi ecology warning flick. Jaden is warned that everything out there has evolved to kill humans. At that point, I imagined a scenario where the high-tech space warrior cuts a swathe through the ranks of bunny rabbits and sheep that confront him before learning to appreciate the benign beauty of the old homeland. Of course no such frivolity is allowed here; the terrain that Jaden crosses resembles Jurassic Park.

The opening half-hour – the Before Earth section – is strong enough to keep you hopeful. These scenes suggest a film of scale and vision but, as soon as they hit Earth, it shrinks into itself. You can almost see the belief seep out of the film as the realisation sets in that this isn't really working. By the end, it has degenerated into a B-Movie mess.

The Smith family have been working on this project for years. It is a perverse endeavour really as it doesn't show either of them at their best. Will has a brave stab at playing against type as an uptight humourless soldier but just comes over as stilted. Jaden has always had to face audience resentment and, though he did OK in The Karate Kid, here he isn't nearly interesting enough to carry the whole film.

AFTER EARTH (12A)

Director: M. Night Shyamalam

Starring: Will Smith, Jaden Smith, Sophie Okonedo, Zoe Isabella Kravitz and David Denman

Length: 101 mins

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