Let a friend/child try a game on iOS?
In general, no. The game developer can store progress on the device locally, on an iCloud / Game Center log in basis (or both) or save data off on a private server / public cloud.

It really depends very specifically on how the game was programmed to behave and you’d need to contact each vendor / read their documentation or experiment to understand how or if game progress and data persist on iOS.

Even deleting an app won't remove some game data and some people love that and others, not so much.


Can I delete an iOS game and retain my progress?