This isn't a thriller in the true sense, it's more like a horror film. It's beautifully crafted and a master craft of character driven story telling. Some of the people's reaction to impending armageddon is irritating, but then I'm guessing some people's reaction to disaster would be annoying.
I was left thinking about this film and it's apocalyptic scenario, for days afterwards. Life on our planet is precarious and made more precarious by the lunatics we elect and share it with. I found the ending to be genius - because it perfectly sums up what this situation would leave us with, were it to come to pass. We'll never know why, we'll never know how and we'll never know the end.