It should have been a match made in heaven: Walter Hill, writer/director of many action and Western classics in the '70s and '80s helming a resolutely old-school buddy-action-noir movie, set in New Orleans, and featuring an aging hitman (Stallone) and a straightlaced young Asian cop (Sung Kang) who team up reluctantly to solve a couple of murders and uncover a real-estate conspiracy by a slimy lawyer (Christian Slater) and a corrupt African potentate-on-the-run (Adewale Akinnuoye-Agbaje). The bad guys have a nigh invincible mercenary on their side (Jason Momoa), who fights Stallone in a fire-ax duel. And to top everything off, Stallone even has a hot daughter (Sarah Shahi) who earns a living as a tattoo artist and gets involved in gratuitous nudity!
So what went wrong?
Somehow the screenplay manages to botch the most fundamental aspect of a buddy movie: the buddy relationship.
Stallone the old-school assassin and Kang the by-the-book geek cop hate each other from the start. And they spend most of the movie in each other's company - hating each other all the way through. In other words, the relationship is static instead of dynamic. The same story beat is repeated over and over. Cop wants to arrest assassin when all this is over, hitman is pissed that cop doesn't respect him after saving his life for the umptieth time.
The only progression occurs at the very end - and then it's a pretty big leap from mutual loathing to respect. The emotional change feels forced and way overdue.
Now, there are a few funny scenes between the two, especially the driving scenes in Stallone's car, and both actors have a good rapport going. But even these scenes stick to replaying the same beat: Stallone trumps and humiliates Kang, no matter the subject of their conversation. There's no real debate: Stallone's way is correct, Kang's is wrong, and we're never allowed the opportunity to forget it. Whereas any decent buddy movie made sure that the 'wild guy' learned a little bit of restraint from the 'square guy', and the square guy got to release his inner beast. Cliché, yes, but at least it works. Sabotaging this character dynamic without replacing it with something different and/or better, just cripples the film. And it makes the lead characters come across as very one-dimensional (and I'm not talking about the hottest boy band on the planet now).
It doesn't help that the conspiracy that gets revealed is so ordinary and uninvolving. The external storyline doesn't provide enough intellectual stimuli to keep the audience enthralled/surprised/excited througout the film. Neither villain has any depth or complexity (though they are plenty stupid). Their only reason for existing is so that they can send an army of goons to trouble our battle-happy heroes.