Battle: Los Angeles is a better than expected actioner in the tired alien-invasion genre. The dialogue is subpar and wanting, but is adequately compensated by the gripping action scenes. It's like Black Hawk Down, but instead of fighting Al Qaeda on the streets of Mogadishu; the Marines are in fierce, house to house combat, against an alien horde. Director Jonathan Liebesman does an excellent job of immersing the audience in combat. There's never a doubt who will win in the aliens versus marines battle, but the fact that it's interesting from the first frame to the last is an achievement.
Aaron Eckhart stars as the battle-hardened, but psychologically wounded Staff Sergeant Nantz. On the verge of retiring, he's called in to help lead a company of Marines into an alien siege of Santa Monica. The film gives no exposition whatsoever as to why the aliens are attacking and what they want. The focus is singularly on the Marines as they attempt to rescue civilians and get out of the city.
What makes Battle: Los Angeles work is the intensity and grit of the fight. Liebesman knows he has a paper thin plot and must create a situation where the audience has to be invested in the well being of the unit. Other films have done the alien invasion on the macro level, a la Independence Day and War of the Worlds. Battle: Los Angeles rests its fate on Aaron Eckhart's ability to make the small situation believable. And that's no easy feat because the writing is so weak. Now anyone seeing this movie expects an ass-kicking explosion-fest from the go, so I don't particularly fault them on the script. Too many films fail on both fronts, the writing and action, so they deserve credit for delivering an entertaining film.
We never find out anything useful about the aliens. They are generic, and serve the purpose as the enemy. I was actually waiting for some kind of reveal, but it's probable better that there isn't one. It would have been lame and brought down the better values of this film. Battle: Los Angeles is a pure popcorn film, a good way to mentally check out for two hours and watch the marines kick alien ass.