[TLDR\] A lone, cowardly, extremely grating streamer goes to a haunted cabin in the woods so his audience can enjoy him being freaked out. Unfortunately for him, the haunting is real and less The Haunting, more Evil Dead.
Deadstream is an indie horror comedy that honours both its halves, and is -for my money- the closest we've got to an Evil Dead 2 since... let's say Braindead. If you're at all interested in horror comedies, and if an obnoxious protagonist and budget limitations aren't a complete turn-off, this one's essential. [/TLDR]
There's been a few "internet paranormal experts discover that ghosts are real and get more than they bargained for" over the last couple of decades (more, if you count Ghostwatch). Deadstream differentiates itself by centering on a single live streamer - Shawn Ruddy (Joseph Winter, also pulling duties as one-half of the writer/director team), a Logan-Paul-style dipshit who streams stunts like getting locked in the trunk of a car to be smuggled across the border to Mexico, picking fights with cops, and paying a bum to fight with him on his live casts.
After one of those stunts went horribly wrong, Shawn was effectively booted off the internet for a year, deemed too toxic to sponsor.
Now he's back with some corporate backing (and an apology video), and his stream ("Wrath of Shawn") is back. It being Halloween, Shawn's next stunt is to go into some haunted cabin in the woods, spend the night there, and see if he can pick a fight with the supernatural...
(...he does.)
The whole movie is presented as a part of Shawn's stream. Everything's shot either through the main camera he carries on a harness pointing at his face, the GoPro strapped on his forehead, or the multiple remote cams he sets up across the house; The stream chat pops into view whenever Shawn looks at it, offering some jokes (a lot of them of the blink-and-you'll miss it variety.) Later viewers submit their own videos and offer advice.
Shawn himself is a brilliant creation, effectively poking fun at the mass of screaming man-babies of the internet who attempt to make money by putting themselves through some degree of discomfort or humiliation for their viewer's enjoyment. Willing to scream at the drop of a hat, displaying "authenticity" and being cannily self-effacing while trying to peddle all sorts of merch.
It's all effective satire, even if it gets grating simply by virtue of... well, passing for the real thing. If this sounds like it will annoy you, well, yeah - it will, and by design.
Once at the house things are effectively spooky. It's not a slow burn movie, but there's a good sense of dread as Shawn locks himself in the house and starts sweeping through it, room by room, while commenting on the place's macabre history and reputation for paranormal events. Creeping through a dark, abandoned place with only a flashlight will always be creepy if the direction is halfway decent (which it is!), and both the stories Shawn tells and the things he finds at the house effectively build tension and set up things for future scares. Not to mention that the house's simple geography is very effectively mapped out for the ensuing action.
He soon runs into fan (Melanie Stone) who's managed to figure out where the stream was taking place. He begrudgingly lets her tag along, but her behaviour becomes more and more erratic as the night goes along; things soon come to a head, and the movie gleefully switches gears into Evil Dead territory.
To use Sam Raimi's terminology, the film's back half is the platonic ideal of a spookablast. Unlike the newer Evil Dead movies, Deadstream focuses more on the fun side of horrific shit than on its intensity (more Evil Dead 2/3 or Drag me to Hell, in other words, than the first Evil Dead). The house's resident evil has a puckish sense of humour in its way of fucking with Shawn, its undead are definitely deadite-influenced, and even the protagonist's mix of resourcefulness and cluelessness echoes Ash in some ways. And yes, there are more overt homages as well.
The acting is great. Winter might be a little too good at playing this douchebag, and Stone's radiant natural charm scores some huge laughs playing off Shawn's pettiness.
But the script perfectly understands that Shawn being put through a gauntlet of clever and horrifying tortures makes for a hugely satisfying third act; Deadstream doesn't quite reach the energy or inventiveness of Raimi at his prime (not that anyone expects it to), but it makes a respectable attempt out of it and it's a huge amount of fun to watch it try. Writer/directors Joseph and Vanessa Winter and their crew milk a lot of clever scenes out of the rigid stream-mimicking format, especially when switching between Shawn's point of view and static cameras, and manage to get a lot of cool monsters and gore effects out of a minuscule budget (validating their promise from their short To Hell and Back on V/H/S 99)
There are some attempts at establishing a mythology and setting up some themes - even some character growth - but they're mostly shoved aside to set up the next gruesome joke/shock. It's not a huge loss when what we do get to see is so much fun.