I had this idea quite a while ago. When you run a game on a PC, it is running on top of the O/S. So the O/S cuts off most of the operations running, and devotes as much resources to the game as it can. Provides what info the game needs that it can. The game it self is still running on top of this O/S. Why not make the game the O/S?
I will use Linux for my example.
But if you did it like this
The system would be focused on the game alone. The game system would setup all the things a game would need. The graphics environment, networking, audio and user input.
Think of the game system as something like Windows DirectX, only instead of going through windows to the system, it would work directly with the kernel.
So, setup the Game System basics. Something much like a graphics engine like Unreal that has everything a game would ever need. Lighting, shading, etc. Post the new kernel with the Game system, I would call it Direct-LinuX (lol) And release it to the world and see what happens! If say, the unreal folks picked it up and designed there system to work with it such a system would be so smooth, and requirements for pc games would drop a little bit!