Your degree of fondness for the war and/or science fiction genres will make the marines vs. aliens movie Battle: Los Angeles either comfortingly familiar or gratingly obvious.
Viewed as a war film, it's strictly standard run 'n' gun fare. Scripter Christopher Bertolini ticks off the particulars of the platoon's instant backstory with admirable ease but far too many shopworn clichés.
Aaron Eckhart plays retiring USMC Staff Sergeant Michael Nantz, who is called back into extremely active duty when gooey, bipedal extraterrestrials launch a surprise invasion of Earth. He is haunted by memories of the men who died under his command in Afghanistan, and he must win the respect (immediately, since the events depicted here take place within a three-hour time frame) of a new group of soldiers.
Second Lt. Martinez (Ramon Rodriguez) is technically the ranking officer, but he's raw, unproven and, ultimately, indecisive. The brother of Cpl. Harris (Ne-Yo) was one of the casualties in Nantz's prior posting, which results in predictable tensions between the two. Professional badass Michelle Rodriguez is mostly relegated to the sidelines as an orphaned tech sergeant who hooks up with Nantz's ragtag group. Their mission is to find and rescue a group of civilians trapped inside a police station behind alien lines before a wing of B-52s obliterates all of Santa Monica.
Viewed purely from a sci-fi angle, Battle: Los Angeles is even less remarkable. The aliens are scruffy-looking things in armor that use laser-blasting ground forces and unmanned air support in classically strategic fashion. There's none of the popcorn awesomeness of the giddily goofy Independence Day or even the strident satire of Paul Verhoeven's Starship Troopers. This is realistic, close-quarters urban combat of the kind best seen in Black Hawk Down.
Battle: Los Angeles gets points for (gore-free) realism. The effects work is topnotch; you'd never guess this was actually shot in New Orleans. But ultimately, it's likely to top nobody's list of the greatest sci-fi, war or sci-fi war movies of all time.