well, if you add a game to a scenery project, it's a game! Easy! :P
All kidding aside, I don't mean to rain on the parade, but these "X in UE5" are dime a dozen stuff on youtube, basically just harvesting views for a game/remake that'll never be. Some of them have bit more effort put into them than others, sure, but basically none of them are even remotely close to being anything more than pretty graphics demo made by a single person.
The fact that these can be made by a single person is no less impressive though, and farming views is maybe a motive but more importantly this person is showcasing their skill at manipulating the UE editor.
But yeah there's no "game" here.