Well, in all fairness, its pretty bad. If only Karl Urban could keep to one accent, maybe his character would be a bit more believable. And even the Rock, who as we all know was a wrestler, can act a bit better than Karl!!
Anyway, Karl bashing aside, its pretty horrible, not alot of gore, nothing new..Probably worth checking out for the five min first person sequence at the end of the movie.
That said, save yourself the time and play the game instead!