Watched this tonight and it was every bit over-the-top and epically violent as I'd hoped.
It has a bog standard, seen it a million times before corrupt cops, drug deal gone bad plot.
It starts with an absolutely awesome car chase, calms down for 40 minutes to establish the bare bones story then explodes into brutal John Woo style ultraviolence for the remainder of the film.
The city feels like an even grimier and violent version of Gotham City.
Most of the reviews seem to think it's supposed to be taken seriously but I just watched it play out with big shit-eating grin on my face and utterly stupid the action scenes are.
Great movie.