Rob Simpson’s review published on Letterboxd :
Mandy can have Nicolas Cage channelling Jason Voorhees, Bill Duke, Biker Cenobites, Black Metal imagery and Johann Johannsson's brilliant score evoking LPs like Absolutego and Dronevil; none of it changes the fact that the first 70 minutes of this are some of the worst I have seen all year. 67 minutes it takes to set the scene and the concept up. A better writer or director could do that in 20 and keep the visuals in tact, in Mandy everything stops dead to facilitate the style.
Never mind that you probably could've done a fairly good b-movie in those 67 minutes telling the same story. 2 hours this self satisfied mess is; 2 hours of unending psychedelia. The dialogue, like that first hour, is some of the worst of the year. And this thing about Panos Cosmatos being a visionary. I take serious issue with it. Heavy metal albums and red, everything is red. Literally. While it does look singular and impressive, putting the images above all else to such an extent ensures that the film drags its heels so incessantly that I was bored out of my mind within half an hour. It came across as a bit smug, at the end of the day. Oh, and the action is lost in over editing. There is a chainsaw fight but the darkness of the scene and the sheer number of cuts render the scene terrible. Tiger on the Beat retains its status as the movie with the best chainsaw fight.
I hate being so negative about what is already a fan favourite, and already a cult movie thanks to bits like the cheddar goblin - I really do. This movie is exactly up my street, so yeah, I wanted to like this, I really did, but that just wasn't to be. It's with movies like this that drop their pants in search for an elusive style, it makes me realise just how good directors like Refn, Strickland, Argento and Russell are (were). Speaking of Dario and Suspiria; I am so sorry I said all those nasty things about you - I take it all back. Well. All of it save the stuff about the sound editing. That is still problematic.