From a purely viewer's point of view, the movie is bland, predictable and full of cliches. But if you read the book, then don't even bother seeing this movie because it doesn't make any sense. It doesn't even seem to be inspired in the books, mainly because they stripped out all the most interesting happenings inside Area X (I mean, the tower/tunnel, come on!). Not even the true relationship between the characters was picture in the movie.

TL;DR they just wanted to make a movie with guns and monsters inside a shinny sphere.