Have a machine dedicated to gaming, no Internet access, with a swappable SSD. Make a clean OS install. Clone it to an external backup drive, then disconnect the backup. Install and play. If you want to play another game, format the drive, clone the OS from the external backup, install and play. If you want to play multiple games, have them on different SSD drives.
Very good solution. However, what benefit does the user get by formatting the drive every time a new game is to be installed? I mean, the thing already doesn't have internet access and no important data is on the drive anyway. Am I missing something?
Well you have to get the install files moved over to the sandboxed PC somehow. If it is infected and you plug in the USB drive or whatever that goes back and forth, you could spread the virus through it.