Robert Carlyle is probably the best known star in terms of world-wide viewers (from The Full Monty). When you consider that it was mostly a cast of 7 (Robert, two women, two army guys, and two new child actors), they did a good job of carrying the movie. The use of different scenes and locations likely added to this. I think location change and pacing is what makes many good action movies appealing including James Bond movies.
The movie begins with an incident of moral scruples and anguish (shown very well through Robert’s character) that will prove doubly haunting (albeit in a very co-incidental/human-radar way) through the rest of the movie. It ends with the option of a wider playfield for another sequel, which only occurs because adults fail to communicate something important to children. That depth of moral dilema (and the fact that not everyone ‘good’ survives) is what makes this movie rise above the average gore-fest.
The movie was entertaining and worth seeing if you liked the first one – just don’t expect any conclusion.