The storyline is decent, albeit a bit thrown together at some points. The overall gameplay is pretty innovative with things like the team abilities, but when you look past that, it is really just a corridor shooter. However, it's a corridor shooter that still manages to be entertaining past a certain point, which is something that most of them just can't pull off a lot of the time.
I wouldn't really say that it has excessive replay value, but it is decent for a budget shooter. Then again, that's coming from someone who enjoyed Prey and Code of Honor despite the bleh gameplay. >_>...