It didn't sound that good from the IMDb plot summary - I only suggested it to Charlotte and Nicolas because I wanted them to have the experience of the Hyde Park Picture House, really. But once Charlotte had reacted with 'Ooh, yes, I really want to see that', and johnnydefective had enthused wildly about it over curry, I figured it must be worth checking out after all. Those are two people whose film opinions I usually trust.
See, what the plot summaries just don't bring out (although maybe because it is so blindingly obvious given the setting that they felt they didn't need to) is that this is an example of one of my favourite kinds of film - the 'cabin-fever' movie. Like The Thing, Night of the Living Dead or (best of all) Cube, you have a small number of people trapped in an extreme situation - and the rest is really about their character interactions, rather than about the specific setting.
The science of it all is pretty obviously bollocks, and there was also one point where it felt like a huge chunk of footage had just been taken out, causing us to leap suddenly forward to an event which it had seemed a moment before wouldn't be happening for quite some time (I'm trying to be non-spoilery, here!). But neither of those things really mattered. As I said, it's character-driven, and that side works out just fine. There are some tense moments, some unpleasant realisations, and the consequences of some bad (but plausible) decisions to be faced. And of course there is Cillian Murphy, who's already proved his worth in a Danny Boyle cabin-fever movie in 28 Days Later. He manages to do the 'small, vulnerable human facing things too terrible to imagine' thing very nicely.
So yeah - I wouldn't say re-arrange existing commitments to see it, but if you get a chance, it's a good use of an evening.