So my sister and I watched this movie last night.
Her conclusion (and mine, too, although hers was more vehement): If they hadn't tried to tell a story, they'd probably have made a better movie.
As it was, it was an incredibly stupid movie that had really, really cool monsters and explosions. The "Atrox Army," the huge mass of various reptilian creatures serving the villain, was very iconic (for me, anyway-as they say on TV Tropes, your mileage may vary)-it's really kind of sad that it's stuck in such a ridiculous movie.
Probably the best plot point in the movie was the zoo security guard who saw the evil Imoogi, Buraki, eating elephants in the zoo. (Why does a titanic serpent dragon from a celestial realm eat elephants? Because he can.) Nobody would believe him, even when Buraki was literally right behind the person who was "evaluating" his psychological fitness. Sadly, we never see if the dude lived to be vindicated.
There were a few tiny clever moments-some people remarked that the best part of the movie was the one in which a dude phases through a glass door, and an old lady tries to follow him through it, only to bump her head and then wander away confused. (Kind of a cruel sense of humor, but it was funny.) There was also a bit where a scientist was analyzing one of Buraki's scales which was kind of interesting because there was speculation as to where it came from... too bad they ruined that by having some guy show up and insist that it was a Korean legendary monster. (Though the skepticism of the guy who was being told this was amusing, if transitory.) One other thing I liked is that it was a fantasy setting that presented the ancient, powerful creatures from heck as being merely relatively evenly matched with the modern army, rather than far outclassing it-that's too rare.
But there are lots of really stupid things, like a pointlessly evil FBI agent who shoots the protagonist in the head at point blank range... and the dude gets back up, completely unharmed, less than a minute later. Granted, he was supposed to be the reincarnation of an ancient Korean celestial warrior guy or something, and he was carrying a magical amulet that was supposed to protect him, but there's no indication they actually contributed.
Conclusion: If you don't have a high tolerance for stupidity, I'd recommend fast-forwarding any time there aren't monster things or explosions on the screen. You'd still need a high tolerance even if you do (the tactics used by the military are positively abysmal, for instance), but hey, them's the breaks.
(My sister says I owe her now for making her watch it; she was all cynical and cranky for the rest of the evening. Also, she is really offended that it somehow got classified as science fiction even though it's really extreme fantasy.)