The Thirteenth Floor (1999) by Josef Rusnak is an unfairly ignored existential scifi with a secret, cryptic alternative plot espousing the reality of trans-dimensional non-human-intelligences/spirits/gods and humanity's identity therewith.
The official plot is a contrived tale about VR programmers (users) possessing simulated humans (program links) to live out their darkest fantasies, resolving with our simulated hero defeating his user and escaping to an idealised 'real world'. But that's just the cover story.
To decrypt the secret message we have to suppose that there is no such thing as separate 'users' and 'sims'. Rather, there are simply higher and lower dimensional manifestations of the same conscious entities on an eternal quest for transcendance.
The relationship between Hall (the user) and Ferguson (the sim he 'possesses') should be understood as analogous to the relationship between me and my little toe. We're not identical, but my toe is nonetheless me. When Hall 'possesses' Ferguson it is like me focussing my attention on my toe.
The film opens with Rusnak speaking direct to his audience as Fuller, the creator of our simulated world. He has uncovered a terrible truth, and is writing it down for the only person (us) who could ever understand it.