Care for Eyes can lock screen on time, relax your eyes by force.
Disable some windows hotkey when lock screen,like WIN,CTRL+ALT+DEL,CTRL+ESC,CTRL+SHIFT+ESC,WIN+F,WIN+M,WIN+E,WIN+R etc
Disable taskbar, can't switch to another task.
Do you want to adjust gamma,brightness,contrast JUST in game? Do you want to control volume of speaker or mic without mouse? Do you want to have 100 virtual clipboard and 8 virtual desktop? Do you want to control winamp only by hotkey at any time?...