The previews did not show a single bit of the personal lives of the actors in this movie? Why? Because every scene was overly-sentimental and over-acted. The beginning of the movie completely surprised me as we learned a little about each character in the squad. Without it I supposed they would have remained mostly nameless and faceless.
When the first battle scene began I thought that maybe the movie was really starting, but then it quickly became filled with overwrought music and dialog. Really, how many times do we have to listen to the violin strings of heroic conquest?
Also, the aliens started out impossible to kill, but by the end were ridiculously easy, not because of what they had learned, but because Hollywood can't figure out how to do aliens.
In the end even though I wanted to like the movie, I couldn't help spending the last half making fun of it.