Well worth a look, give it a rental.
If the story seems old-hat it's because, well, it is - off the top of my head I can think of three recent films that share very similar if not virtually identical plots - Outpost, The Bunker and Deathwatch. It doesn't help that none of the characters are even remotely likable - a collection of whiny misfits led by a monotonous bore who are trying to break the record for the amount of times "asshole" can be said in one film! They're loud, unruly, unprofessional and you don't care what happens to them. It's kind of a problem.
The film is well shot and well acted (the characters may be annoying but they're believable) with one or two interesting ideas but it's not scary, there's precious little tension and more often than not it's just plain dull.
There's probably some deeper meaning going on - I certainly hope there is - but I fear it's been lost in translation.