Dual Monitors - Forward and Backward Looking
In essence, when playing on a multi-monitor (dual only?) setup, the user will be able to set one monitor to show a view that is rotated 180 degrees about the vertical axis from the main view.
No special HUD elements will be needed as these are visible on the main view.
By default this will be disabled and players with one screen will not be notified of this ability. Only players with two (or more?) screens will have to enable the feature knowing it will come at a render cost.