Killzone 2 is not revolutionary. Killzone 2 is not perfect and Killzone 2 is not frustration free. Killzone 2 is, however, a beautiful, excellently executed first-person shooter, full of satisfying gunfights, explosions and swearing – basically the gaming world's equivalent of a blockbuster action movie. Just like a top-notch action movie, what lies within is polished to an amazing sheen.
Also like a top-notch action movie, though, certain tropes and problems from previous efforts in the genre are carried forward, with no solution except to blind the audience with the light shining from the polished elements, hoping that no-one notices the wrinkles.