Chances are Extinction will remind audience to other zombie or survival movies, such as I Am Legend or even The Walking Dead television series. It uses many familiar elements in this already packed subgenre and honestly it doesn't boast that high of production value. The saving grace is its human drama, which may not be perfect, but acted and crafted fine enough to present a solid survival story.
Patrick (Matthew Fox) and Jack (Jeffrey Donovan) are two neighbors surviving in cold wasteland. Both of them had unusual past which eventually drifted them apart, but they now must reconcile to protect a child from escalating threat. The pace is shifted from present to past regularly to showcase their backstories while the story moves forward.
This method does set some nice character developments, furthermore the actors are definitely capable enough to make it work, seeing that the runtime of nearly two hours revolve around them. It does feel a bit slow at times since the angst and redemption theme are repeated frequently. The movie tries to deliver a few twists, these might not be outright predictable, but not exactly strong and occasionally reaching too far to produce emotional tone.
Actual zombie assault takes much less portion of the movie than the drama, yet it is still made pretty well. Design and effects look better than most of smaller budget flicks. It won't look cheap or campy when the action starts, but it does tend to follow overused path of bald white creature and its quirky antics.
The effort put to personal story and action survival might not suffice to rise above the horde, but it doesn't go to waste since Extinction, despite its flaws, is adequate for a survival tale.