I notice the guy from X-Men gets top billing. I'm guessing he's actually a trained actor, because the scenes with him and the leading lady are really weird. He's acting, and she's... well, saying her lines. They are so mismatched that hit draws attention to how much better he is at it, and the result is really strange.
Better to have everyone not bother trying. When you're the only one acting in the movie, it comes off pretty odd.
That was my thoughts as well, she was really quite terrible while he very clearly stood out, the other girl was not much better either.
What I really found annoying throughout almost all of the movie was the fact that they barely talked, if someone asked a question, they would just stare blankly into space while the other person waited for an answer.
And while the two girls were being undressed/redressed and tortured etc, they did a lot of whimpering instead of screaming at them to *beep* off or to leave them alone, I assume that they assumed they were dead anyway and if it were me, I'd be kicking and scratching at anything that got in my path, they didn't put up any sort of fight, it was weird.