Matt Hurt’s review published on Letterboxd:
Aside from some insanely detailed violence in a couple of key points, Possessor is a little slow and unoriginal for my tastes. It plays out like an amalgam of Black Mirror, Inception, and The Matrix but doesn't do anything unique with the concepts it draws from them. Instead, it leans into this cerebral attempt to clutter the viewer's perception of what's going on instead of engaging the audience in an interesting story. It rests on its laurels of shock and awe rather than coherence.
It takes a long time to get going. When the movie reaches its final act, it comes about 45 minutes too late.
There's some graphic violence that's occasionally outright gratuitous. If that's your bag, you'll like some of Possessor.