One unique-ish thing this movie does....
...that speaks to how well made it is,
is how long it really takes the action to get into the hands of the "main characters."
Denzel and Chris are introduced, but are pretty much kept on the periphery for the first 30 minutes or longer.
Interesting to see a movie, especially an action-y one, that doesn't bring the heroes into the fold for a third of the movie.