Raphael Georg Klopper’s review published on Letterboxd:
It may be easy to see and here (apart from his great and underrated "The Nice Guys") the why Shane Black is so acclaimed by many as a fantastic both screenwriter and director (certainly not for Iron Man 3). By creating here a Noir-themed storyline with a buddy-cop touch reminiscent of his excelent "Lethal Weapon" scripts, managing to not only make a clever and creative satire about the stars live in Hollywood, but also creating a new way of communicating metalinguistically with its audience: by not giving a crap to what they think or say.
Logic here doesn't exist, and if you wait for it to show up, you will be left disappointed. The plot often jumps and to the mundane and pointless (and hilarious) interruptions of its narrator and protagonist Harry Lockhart (a superb Robert Downey Junior) and its daily interactions with the others (excellent) characters to later return to the mistery/investigation plot that appears to have thousands of loose ends but that can be highly intriguing from start to finish. Not to mention the constant tone shifting, the film is sometimes violent and serious when it wants to be, and it's funny and pitiful without mercy, and manages to be both perfectly fine. Still relying on surprising bangs of action and serious existential drama, with Black constantly playing with the generic narrative paths (without ever sounding generic) and his dynamic and creative editing. And when you come to even think that this is a cynical movie and it will end with a tragic note of a good Noir movie, it turns on the "fuck-it" mode and ends it exactly the way it wants, and little cares what you're going think about it, and that's why is so annoyingly pleasurable!
Without sparing on the praise of its fabulous cast. I will never understand why Val Kilmer never gets more chances to show how great he is like here, every scene with him is a perfectly mixed blessing of humor and seriousness with his supposedly gay detective, Gay Perry with all his effeminate personality locked up and his badass motherfucker mode about to explode, where the only layer of mystery around its character is whether he's really gay or not (and it works, and it really leaves you in doubt, that's oddly bizarre and clever ...). Still accompanied by an already mentioned excellent Robert Downey Jr returning with everything here after years, and a fun and enthralling Michelle Monaghan.
I just have to ask to Shane Black to show off more of his incredible talent as a director and writer, not with generic blockbusters like his silly Iron Man 3, but with creative, daring, and extremely entertaining movies like this little pearl.