Just saw this movie this weekend (it's on Amazon Prime right now) and I'm still wrapping my head around it. It seems like a good film to analyze to show the difference between character vs. player.
So there is one character played by many different players: The agent, Jane, John, and the Fizzle bomber. John is the MC, as we are seeing the story mainly though his eyes as he comes to understand who he is. The agent (Ethan Hawke) is the IC. He knows way more than the audience and is trying to recruit John.
There's a whole section of the film (maybe 30 min) of only the MC story, where John relates his entire backstory via flashback and narration. It did drag the film down a bit, though in the end it's more tied into the OS story than it seems.
I think the OS is in psychology, mainly because the goal appears to be "Becoming" -- it's all about the agent recruiting Jack so that that he "becomes" the agent and keeps perpetuating this causal loop. I'm still confused whether the end was success or failure -- the agent kills his future self, thereby ending the paradox cycle, though it seems to continue at the end, so I'm thinking he failed.
Though I could also see an argument for putting the OS in Universe as all the characters are "stuck" in this temporal paradox, with a Goal of Future, maybe (The agent trying to change his future.)
Anyway, it's a very head-trippy film and seems like a challenging one to analyze because of the character/player overlap. If anyone else has seen it, would love to hear what you thought.