The System, a far-ranging strategic machine, is slaughtering human beings by the millions. As the pilot
of the star fighter AFX-6502-ZANAC, you are humanity's only hope. The System is equipped for fighting against a multitude,
so you flying alone may have a chance to defeat this sprawling enemy. Your primary goal is to destroy the central base of
the enemy's machine troop.
The ship you control moves vertically and uses eight special weapons (in addition to
its conventional weapons). These weapons include: the All Range Weapon, which fires into controlled directions; the Straight
Crusher, which starts off slowly and crushes enemy weapons; the Field Shutter, which acts as a shield; the Circular, a weapon
which circulates around your ship; the Vibrator, which vibrates left and right; the Rewinder, which climbs up slowly and decelerates
as it falls; the Plasma Flash, which acts as a smart bomb in the air; and High Speed, which acts as a smart bomb on the ground.
You can only use these weapons one at a time.
As you fly along, shooting everything in sight (in the air and on the
ground) and catching weapon power-ups, you will be confronted by a variety of enemies, each of which fly and shoot in specific
patterns. For example: a Duster is a rock that fires at long range; a type one Umber scatters bullets in seven directions;
and a type two Veybar slants down, reverses, zooms, and then shoots bullets.
Zanac, which is composed of twelve levels
of play, is unique in that it uses something called ALC (Automatic Level of Difficulty Control Function) which is programmed
by artificial intelligence. The strength and quantity of the enemies change according to the player's skill level and
method of attack. Also, the place where the enemies appear varies game by game. One example of this is that the faster and
more frequently you shoot, the harder the game gets relative to the player's and enemy's skill level.
At certain
points during the game, the vertical scrolling will stop and you must destroy the boss of that fortress within a certain time
limit.
