Attack of the Unknown

An alien invasion sci-fi/horror/action flick. The first half of this movie plays out on an impressive scale and includes a big shootout, massive explosions, and a huge alien ship hovering over Los Angeles. The muzzleflares on the guns during the shootout were clearly added in post and the CG explosions aren't always convincing (though sometimes they are), but that didn't stop the movie from featuring a lengthy shootout and multiple explosions.