So I did see this today.
It's not bad but not nearly as good as it could have been.
It settles on more of the "bad seed" trope rather than truly digging into why a super-powered kid might break bad, even though his parents seem to have been decent-enough parents to him. It feels more like the "momcentric" telling of the story rather than the boy's perspective ("OMG my kid just hit puberty and I don't know who he is anymore!"), it becomes more like a horror film where there's an unstoppable monster is taking people out one by one. It's about average in that regard, although the character design is pretty great.
One piece of weirdness -- the kid's name is Brandon, but they cast Badger from Breaking Bad in the movie as well, whose actual name on that show was Brandon Mayhew... so I had to keep reminding myself who the name belonged to in this film.
I think it was smart for them to lean into the R rating, though. I mean, you can't really do a film like this justice by trying to cushion the damage he could wreak. There's some real gruesomeness here, though. It's definitely a second-tier monster/slasher film just pretending to be a superhero film; I just wish it had had more psychological exploration and feeling like Brandon was struggling with who he was. I think one of the best part of the Superman flicks we've seen (and in the comics as well) is the grounding of Clark Kent -- basically Superman can pretty much do whatever the hell he wants, but the Kents imprinted on him to the degree that Superman actually views himself as human (rather than Kryptonian) in terms of his loves, affections, and identity. When a person cannot be reasonably be controlled, they are controlled only by their own moral conscience, and his identification with humanity is why Superman doesn't go down dark paths. It seemed like Brandon had an adequate moral conscience, so it's not clear why he is sliding down here other than his lack of being human -- i.e., he's at the mercy of his biological origin, which doesn't really make for compelling viewing.
Better films? "Chronicle" (2012) is another starring Dane Dehaan and Michael B. Jordan, where a superpowered teen breaks bad, but it's far more clear why DeHaan's character takes a dark turn there. Of course, de Palma's "Carrie" is the same kind of thing, where puberty brings superpowers to a teenager who then is tempted to go bad due to the bullying in her high school, but then it's still legitimately shown why Carrie might take a dark turn... in fact, the question there is how she grew up with a batshit crazy fundie mom and still possessed any kind of real conscience. If you want to make an emotionally resonant film, you have to deal with a protagonist who is tempted to go bad and is warring over the state of their own soul when offered limitless power -- not powerful people who either have no moral agency or who don't care to try to do good. (Heck, even Star-Lord got this right in GotG2 when he is offered the powers of a god but can't forget his friends... It's even embodied in various religious, like with the temptations of Jesus who chooses to not use god powers to save his own life or gratify his own desires...)
