I've heard games be described as agency fantasies. It's taken me a while to unspool that thought -- a game is a simulation, so nothing that happens in it matters. Why should I care about the suffering of a fictional character, the death of a fictional world, getting one ending over another? I know not to, but I still want agency.
Agency-as-Student is a tenet-in-development. The games I want to play are agency fantasies of exploration and learning. I can read an incredible book and learn something new. The world is full of great writing sharing great perspectives. A book is a guided tour; when we're in tune, I am exploring and learning hand in hand with its author.
Games can respond to what I want to learn. The agency I have is over my own exploration and learning, my own experience. The agency fantasy is not the fantasy that what I do has an effect on a virtual world without meaning, but the fantasy that I can choose what happens to me, and that I can design my own experience around what I care about.
(Let's not get into the topic of multiplayer games today.)
See Time Loop Nihilism (https://newforum.droqen.com/index.php?topic=133.0).
If there are no material consequences, why do my actions matter? Being "stuck in a time loop" is a specific case of the more general "embodied in a space with no consequences". The conclusions drawn in that thread and explored in Geller's video effectively come down to - you as an individual are still impacted; you are outside of that consequence-free space; the impacts on you are what is meaningful, not what happens inside.
The question of "What agency?" in game as agency fantasy must ultimately be answered with "Agency over self."