Isn't UWP games in the Windows Store what you are looking for? For example, all Xbox Game Pass games are installed via a virtual read only filesystem (XVD Disk

Isn't UWP games in the Windows Store what you are looking for? For example, all Xbox Game Pass games are installed via a virtual read only filesystem (XVD Disk Driver). If you need to mod a game, there is an optional setting to unlock write access.