Continuity: Toward the end, Carmen Ibanez gets stabbed through the shoulder when she is brought before the big master alien thing. If you were to sustain such an injury, there would be so much swelling, not to mention just destroyed tissue, that you wouldn't be able to move that arm for weeks. Yet a few minutes later, she is seen hefting around a very large assault rifle, and seems to have no difficulty. I guess it's a pretty standard action movie "heroes can temporarily ignore injury in order to save the day" kind of oversight, but it just seems exaggerated in this case, considering how severe the shoulder trauma looked.

Other: After they attempt to rescue the reporter during the first battle, Rico shouts to the others to go. Watch behind Rico. Apparently, the stuntman in the background is supposed to react as if he got impaled by a Warrior Bug. The Special Effects Department must have decided not to add the Warrior Bug after all.

Revealing: When they are learning how to throw knives, the guy gets one thrown through his hand. If you watch this in slow motion, blood starts coming out of his hand before the knife hits.