Alien invasion movies have been done many ways, by many filmmakers, and there's very little you can do that is genuinely innovative. In the case of "Battle: Los Angeles," the solution appears to be strip it down, soup it up, and let it rip, and in the film's best moments, the approach works for them very well.
Aaron Eckhart stars as Staff Sgt. Nantz, a career military man who is assigned to a unit of marines when a meteor shower turns out to be something far more intentional and malicious. The film actually opens with the Marines in a helicopter, en route to their landing zone, explosions all around them, the invasion of Earth already at full tilt. I wish the film didn't back up after that opening to give us 20 minutes of exposition we don't need, and you can almost hear the studio notes during those sequences.
"Well, we need to give Nantz some personal stakes. Let's explain who he is and establish why this mission is important to him, and let's meet some of those Marines and show who they are and make sure our audience knows them all before the heavy action kicks in." The thing is, all of that is covered on the fly during the action, so the early explanatory stuff feels redundant, and the film would seem much more unconventional and bold if they just dropped us into the situation, sink or swim, fight or flight, and let us figure it all out as things unfold.