Michael Leber’s review published on Letterboxd:
Better than I remembered but that's not saying much.
This demystifies a lot of the mystery in the rest of the films in a way that isn't beneficial and makes things less scary. The choice to give Tobi corporeal form as a black mass of goo was a mistake and doesn't work.
The 3D effects hold up a little better than I expected on a standard 2D screen, but there are large portions of the film where the camera is just moving around while you're supposed to be in awe of effects you can't fully appreciate.
A significant portion of the movie is spent watching other characters witness events we've already seen from a better film. Katie and Kristi's actresses do return for new footage, but the choice to sideline Grandma Lois for this shaman character is bewildering and makes Lois far less threatening than she was in PA3.
For what's supposed to be the end of the series, the way this ends just implies that this is gonna keep happening. We never learn what Tobi's real goal is here (is it what happens? Because there's no reason given why he'd want to do that) and while the alternate ending is more interesting neither are fully conclusive.
Hoping Next of Kin connects in some way to remedy this lackluster conclusion.