Probably not worth 5 stars, but these star reviews tend to be all or nothing, and this film was surprisingly good.
It's your standard elite ex-military against corrupt small town cops trope, but, while still far fetched, it is a much more realistic offering with much more reasonable people and circumstances.
It was well written, with understandable and relatable characters. The acting was actually excellent all round, and the pace felt right for the circumstances; neither hectic nor subdued. A very good watch.