Operation Fireball is a horizontal scrolling shooter viewed from above at an elevated angle, with the screen scrolling constantly from left to right as you use various modes of transport to get to a base to blow up a submarine. Between each mode of transport is a small animated scene as you move from one to the next and the modes are car, speedboat, ski, motorbike and helicopter. You must shoot or avoid the enemy in various vehicles or on skis, as well as avoid obstacles like rocks, oil patches and trees. Helicopters fly overhead and drop bombs while missiles fly from the right to the left and can only be avoided. If you are hit by anything then you lose part of a shield gauge but when not being hit increases it and if it empties then it is game over. Less