While the setup is good, the action is decent, it slowly devolves into a suspension of the suspension of disbelief.
It's not all the standard action stuff that does that, it's the amount of wounds the protagonist sustains over the course and how he keeps trucking on despite that.
Without spoiling anything, the ending was terribly unsatisfying too. It feels like a lot of waste, where they reached an "I give up" moment and just did whatever. Enjoyable with a disappointing ending.