Michael Stuhlman’s review published on Letterboxd:
Second watch and decided to bump it up to a 4.5. Easily one of my favorites from last year and one I never expected to like as much as I did. It's effectively chamber-horror. Replicating the effects of Dementia much in the same way Sound of Metal replicated hearing loss. For me the best films manage to incorporate there thematic basis into the very structure of the filmmaking and it's never an easy task. But the writer director here really blew me away with his sense of control. The swapping actors, claustrophobic apartment architecture and sheer dread of a real world possibility for anyone just makes for a damn compelling film. What's more is it's relatively short at just 95 minutes and that works as a major advantage. It also rewards second viewings by opening up the timeline a bit.
Perhaps the most compelling and difficult aspect though is that it attempts to find truth in the story from an inherent unreliable narrator. While it's easy to question the the unreliable trope and use it's built in ambiguity I don't think Zellner flinches on the utter devastation of what it's like to simply not understand your own life and story anymore. We may not be able to precisely trust what's happening here, but Hopkins character is always believing exactly what is happening and so his own truth is real and observed.
I definitely see this one gaining a nice following, especially when looking at it from different angles. Oh and just to reiterate this may be the most singularly frightening film I saw all of last year.
I hope I don't get dementia.