Perhaps the biggest problem with a film like this is how to market it. Many years ago in a comedy routine, I think Steve Martin was discussing, with a straight face, how to make appealing titles versus bad titles. He said something like "Starting with love always sounds appealing. Like 'Love in the time of...' that will catch people's attention. Then he went on to say you wouldn't want to end that with "the plague". "Love in the time of the plague"--that would NOT be a good title. That's the movie we have here: Love In the Time of the Plague.
Most people writing reviews don't like it; their complaints seem to fall into a few categories: That it's unscientific, as in "The winds don't blow in that direction". That the story isn't linear, and some people found that a bit hard to follow (probably while they were Facebooking at the same time). That they were expecting a hard-on disaster movie and instead what they got was a relationship movie. That there were "too many metaphors". Well maybe it's just trying to establish a bit of cosmic balance, because most movies anymore seem to have NO metaphors at all...
You can separate people into two basic groups: Those who HAVE seen, even owned and used, the EXACT brand of liquid soap referenced in the movie, and those who HAVE NOT! Sadly if you are in the ever-growing latter group, you'll miss the comedy of the references to it here (yes, in my opinion, it was funny).
If you want a disaster movie to play out like some kind of future history lesson, completely plausible and grounded in fact, then what the heck made 2012 so popular? No, I don't think most people care that much really, whether an end-of-the-world story is scientifically completely plausible or not. It's FICTION! Does it tell an interesting STORY or not?
Now we come back to the basic problem of finding your audience. As soon as you describe the essential plot line, everyone thinks, "Oh--a movie about the END OF THE WORLD....hmm...I like those kind of stories (in which case, you probably don't like the movie" or I DON'T like those kind of stories...in which case, you probably don't even bother to watch a movie you might have enjoyed.
Hey--it's not like the end of the world is THAT terrible. [Or, more properly speaking, what appears likely to be the end of mankind]. There's a silver lining to every dark cloud you know. No more rush hours to endure! No more worries about funding social security!
More seriously, I actually did enjoy the film. Yes, it's a bit on the slow side. It also keeps essentially the same pace all the way through. It starts slow...and stays the same. Along the way in what seems a quite simple story, the writer(s)? and director manage to cram in an awful lot of observations about human nature.
These were, generally speaking I thought, quite good actors and actresses appearing in a straight-to-video film, that does not even have any special features available on the DVD (except subtitling--thank God, there's at least that much). So, either they were all desperate for a few dollars, or they all found the story interesting enough that they wanted to be a part of it. Frank Langella, playing the part here of a scientist in the twilight of his years and deeply regretful for the research he did, was the most familiar face to me. Rosario Dawson and Teresa Palmer both just looked so good on the screen I didn't particularly care what they were doing, and Gena Rowlands gave a fine performance as Langella's wife. But pretty much everybody gave good performances.
In summary, this is not your usual disaster movie. Nor horror movie. Nor your usual relationship movie. Nor sci-fi. Certainly not a comedy, though a few scenes were very briefly funny. It does have some elements of all those things, but it's more a musing on the nature of mankind, as seen through three couples in particular. I watched it straight through in one sitting, and found it worth the time spent for one viewing.