I went with great expectations as a big alien(s) fans and...it was a big waist of time.
in short as my english isn't good enough
-Many things where not explained in the movie, or I didn't got it...
example without spoiling (why did he do what he did at the beginning, why did they do it, why did they change there mind, what was the evolution...etc?)
-Personages where so... simple.
-Where was the horror?
-you have seen the trailer, well you have seen all the actions in the movie.
-story is so simple