Minecraft is kinda cheating, because Java, and even considering that it takes a bit of hacking. Alternatively you can sideload the iOS version.
While at the same time you have (running on Rossetta):
* Deus Ex: Mankind Divided
* Dying Light
* Rise of the Tomb Raider/Shadow of the Tomb Raider
* Dirt Rally
* Metro: 2033, Last Light, Exodus
* Mafia III
* Middle-earth: Shadow of Mordor
* Mad Max
* Sleeping Dogs
* Batman Arkham City
* Bioshock 1 & 2
* Borderlands 2
Dual booting isn't working and likely not any time soon as Microsoft does not intend to support Apple M1 [1]. And I doubt Apple have intention to port their GPU Metal Drivers to Windows. ( Compared to using AMD Drivers on Windows in the old days )
He will likely need to use some sort of VM solution like Parallel. [2]
[1] https://appleinsider.com/articles/21/09/13/microsoft-says-wi...
[2] https://www.engadget.com/parallels-desktop-17-m-1-mac-perfor...
The problem is gaming isn't exactly a Mac thing. From Game selection to general support on the platform. So really performance should be the least of your concern if you are buying a Mac for games.