Heya. Sorry to bother. Ya wouldn't happen to know some puzzle games that revolve around the player making multiple saves, and hopping between saves, wouldja?
Assuming this was prompted by my recent post on cheap metroidvanias, you might continue the theme and check out Vision Soft Reset. It's a time travel metroidvania where checkpoints function as save states, such that fast travelling returns you not only to where you last visited a given checkpoint, but also to when you last visited it.
This is what the fast travel interface looks like, for reference:
Functionally, it's keeping multiple save files as a core mechanic, with the wrinkle that certain very specific things are tracked globally across all saves – sort of like how some games have a layer of meta bullshit whereby actions in one save file can affect the state of other save files, except here it's just 100% diegetic.