This is a movie that is attempting to capitalize on the teen novel craze that has brought us The Hunger Games and Divergent series. It failed miserably. The movie started out pretty decent and the effects of the first few "waves" were cool. But then it just went to crap. I don't know if you can put it on Moretz being not as good as Jennifer Lawrence or Shainne Woodley, but it was just seriously lacking any quality once the special effects stopped.
I wouldn't recommend anyone bothering with this movie. It's a pretty big waste of time and I seriously doubt that it will do well enough to warrant making a series out of it.