Saw this tonight, my local AMC is doing something weird where Aladdin is playing during the day on IMAX/Dolby and Brightburn the last two night showings in Dolby. Doing the same split with Godzilla/RocketMan next weekend, but figured I might as well see Brightburn in Dolby while I can.
I really enjoyed it, the kid is CREEPY AS FUCK and a great actor. He's like a young Kevin Spacey, hopefully not as rapey. I really liked how all the characters behaved rationally and what they did made sense, and every moment of the movie felt like it was driven by a single idea "what if superman was evil". Very short clocking in at 1h30m but felt a bit long for some reason. Extremely low budget ($6m) so hopefully it does well and spawns some ripoffs/etc. The casting is great, Badger from Breaking Bad is in it as is the guy who played Pam's first warehouse boyfriend in The Office, he and Elizabeth Banks are fantastic. Damn she's still hot.
If you like comic book movies I think you'll enjoy this. Do not take any kids, there are a few gory scenes. Nothing spectacular effects wise so might as well see it at home if you don't wanna drag your ass out to theaters. I hope some day DC rips off the basic idea and puts it into a $100m+ movie, would love to see this with a massive visuals budget behind it.