Michael Pattison’s review published on Letterboxd:
An actual terror attack is reworked into a home-turf tourist movie: a real-time horror film complete with the kinds of clichés (a heroine returning to danger zones, creepy footsteps outside a tent, gunshot jump-shocks, and so on) for which a genre effort with more schlocky, less arty credentials would be taken to task. The persistent specificity of the opening sequence (dates, timestamps, locations, CCTV footage of the Oslo bombings) hints at a verisimilitude but Poppe, who lacked the guts and talent to make a bad film, couches his relentless mediocrity in a fictional framework (based on detailed research though but!) alluded to in the final on-screen text (which also reminds the braindeads in the audience that Breivik's massacre was "politically motivated").
I was surprised to discover afterwards that Poppe was born a few months before my dad and is therefore a grown man. Also a surprise is the fact that this isn't a directorial debut: what's his excuse for not knowing that shooting a narrative feature in a single take places enormous demands on narrative content (was Viktoria this boring?) as well as your performers, who are here tasked with acting out a bunch of hyperventilating deaths and scenes based around conflicting communication. The camera shifts in and out of focus, 'tactfully' alluding to threats or escalating panic depending on its mood, chasing its protagonist from one muddy retreat to the next. But there's no actual rationale for filming any of this in one take, because the idea that doing so makes for a more 'experiential' ordeal is a critical myth. So the execution is the concept: spectacle alone becomes its own insight. A little girl dies in protagonist Kaya's arms and the camera tilts down so that we see the vibrating phone on her chest and that it's the just-murdered child's mother calling from home. This is style as emotional content: that's fine, but I think I'm done with this kind of insistent and frankly artless dramatic irony in the service of What Went Down On a Very Bad Day (the final onscreen text, as if to vindicate Poppe's aesthetic decisions, also informs us that the island massacre lasted 72 minutes).
Are films ever really immersive, truly? I mean, I'm never not aware that I'm watching one. But of course none of this will stop empathy-machine subscribers speaking on the world's behalf with their earnest lily-livered moralism about how this is such a Necessary Film. The two critics either side of me in the press screening this morning were crying so much that they managed to jot down only three notes between them. The victims deserve better.