A cleverly thought-out concept and well-researched script keep claustrophobic science fiction thriller 'Sunshine' afloat, despite the best efforts of its ending to drag it down.

Fifty years from now the sun is in danger of burning itself out and dying, and only a small group of select individuals can prevent the end of the world. This has all the hallmarks of a classic sci-fi adventure, as a group of eight astronauts board the Icarus II spacecraft, armed with a payload bomb, which, if detonated properly, will reignite the dying sun and in turn save everyone on earth.

But the mission is not a simple one. The spaceship has a crew who are spending far too much time in each other's faces. Tempers are flaring and everyone is eager to save their own skin when a drama hits. Then a random distress signal from the original Icarus mission forces the ship's physicist Capa (Murphy) to make a tough choice, one which isn't popular with everyone on board.

Murphy teams up with his '28 Days Later' director Danny Boyle again here and proves that he would look good acting out a task in charades, turning in yet another faultless performance. His able supporting cast, which includes Chris Evans as the cocky Mace, Rose Byrne as the threat of romance Cassie and Michelle Yeoh as the amicable Corazon, complement him nicely within the restrictions of their character limitations.

It's hard not to notice though that a number of opportunities for character development have been missed, in favour of painting the crew of scientists as a very unfeeling and self-centred bunch when it comes to the crunch. Relationships are thin, back-stabbing is rife and there seems to be an unhealthy need for self-sufficiency amongst the eight crew members.

Up until a certain point, 'Sunshine' is a good movie with some great acting. It starts off with the potential to be a really decent film but a few bizarre, and highly unnecessary, twists later this sci-fi has, much like the mission it depicts, lost direction. It's a shame that these ridiculous touches at the close leave a lasting impression because the original concept was a plausible one and the special effects paint a pretty impressive scene, both on board the spacecraft and outside.

'Sunshine' threatens to be so much more than it becomes, which is what makes its downward spiral all the more disappointing. That said, up until 20 minutes from the end, it remains very watchable indeed and has a lot to admire. It's just a pity that it was allowed to bow out in such an unfitting manner.

Linda McGee