The soldiers are supposed to be special forces but they act like amateurs. They split up, fire at nothing, read porn, make out with sexy ladies who show up out of nowhere, don't keep an eye on the people who just tried to attack the group, and don't listen to the priest who has managed to survive whatever is going on in the lab.
One woman's unborn child shows up as a little girl and she follows the girl off into the tunnels. Seriously? You know it's not really your child, but you follow it not once, but two different times. How stupid are you?
When you reach the end of the movie, you'll be sorry you sat through it because the payoff it not worth it.