Also known as SPL3. It's the third in a series of martial arts films. See https://en.wikipedia.org/wiki/SPL:_Sha_Po_Lang
Paradox appears in the wiki list of neo-noirs 2010-2019: https://en.wikipedia.org/wiki/List_of_neo-noir_films_of_the_2010s#cite_note-28
It makes it in there by virtue of a Chinese article or review that calls it noir: "(The feature of Paradox is on its raw feeling, of noir, of cool, none of them are not included.)"
The film gets high marks from reviewers and martial arts fans as did SPL1 known as Kill Zone. I haven't seen the second in the series. I attest that Paradox is a very good action noir film. It's never boring. If one is looking for how Mitchum would handle the role, definitely go elsewhere! The acting style here is far more "hot". The words "of cool" do not apply, in my estimation, apart from one being able to say that the fights and overall results are cool.
My review of Kill Zone went like this:
Hong Kong noir with stunning martial arts sequences, 3 December 2013
"Kill Zone" doesnít dish out all black and white men, on two sides of the law. The cop squad is bad, rigging deaths, but its lead (Simon Yam) is godfather to a little girl. The head gang leader also has a delicate wife and child. He has more dignity than the cops.
A new cop squad man is coming in. The one in place now has brain cancer. These two conflict. The new man, Donnie Yen, is a martial arts expert, and the weighty gang boss, Sammo Hung Kam-Bo, is too. Look for a climactic fight like nothing you have ever seen. Itís not the only one with Yen.
Sammo, a very strong actor, is boss in his scenes and even when in a cell. He can hardly be put down. His agility is a big surprise.
These men live in two worlds. One is a tender family world that touches their hearts. The other is an energetic wild world where you canít hardly tell the men apart on two sides of the law.