Trivia: In the first level, there is a balcony behind the command post. In the food shack, there is a radio on the ledge. Use it, and it will talk about why North Koreans evacuate the island of some volcanic activity.
Other mistake: In Assault, Pyscho's mouth doesn't move when he keys in the next objective after you destroy the last AA. You can see this on the crane with Pyscho on it or binoculars.