Feedback:User/Lucho/Lower CPU usage while minimized

Change the behavior of the game process so that it burns less CPU time while the game is minimized. As it is now the game always consumes the entire CPU time resource of the system. It seems that the game already recognizes the "minimized" state in the sense that it can mute the sound while in it.

Avoiding unneeded CPU usage is good for laptops that are powered by batteries. Sometimes unexpected/urgent circumstance can arise where one has to minimize the game and do some other tasks on the computer while keeping the game running (because he is in the middle of a mission and does not want to start it over again). Then if the game still consumes all the CPU time, this could impede the other task he wants to perform if it is CPU-intensive too.