I, like many others, was impressed by the star rating of this book however it really does not reflect the quality. Amazing really that The Road is rated the same.
The book has an interesting premise, an astonishing shocking premise. But the way it is told is very mundane; aside from a few admittedly exciting, though unoriginal, moments. It's told in tedious detail, micro-explanations like how the main character tied her shoes after she put them on (obviously), or turned the handle of the door before opening it. As another reviewer says, you could probably cut the book by a third and make it better.
The main character is just not interesting or believable. I was horrified when I got towards the end and realised there wouldn't be a conclusion and it was a book one of a series. Should have looked closer, I felt robbed of even a conclusion. It even seemed a random, bizarre place to stop. Indeed it never really got going.
I don't know how people can be so enamoured with this. If you haven't read The Road, just read that instead. It's a horrifying realistic portrayal of the human consequences of an apocalypse. On finishing I spontaneously started uncontrollably crying, weirdly the only time I have cried in about five years!