Controls what actions are allowed and how rendering/collision works.

Mode	Value	Description
NORMAL	$00	Full player control, collision active
SCROLL_IN	$01	Terrain preview at game start, no input
OVERVIEW	$02	Attract mode demo
REFUEL	$06	Over fuel depot, adding fuel

During SCROLL_IN and OVERVIEW, player input is ignored and no collision occurs. During REFUEL, fuel is added each frame and collisions use plane position instead of missile position.