I've installed and played "Ice Age Adventure". I played for some time and now I want to reset the game. I uninstalled it and re-installed it, but I get the same game progress. It's helpful most of the time, But what if I want to restart the game?
The save data is saved in
%LocalAppData%\Packages\A278AB0D.IceAgeAdventures_h6adky7gbf63m\LocalState (for me, the encoded strings might be different for you).
Reinstalling the game cleared the save for me, so if that folder is left behind after uninstalling the app, try renaming or deleting it and then installing the app again.