Vertical scrolling is employed to good effect in this implementation of
a Caverns Of Mars-type game.
Under joystick control, the player's cruiser continually descends
through canyons, running a gauntlet of firepower spat out from enemy
tanks and cannons embedded in the canyon walls.
By skillfully positioning the cruiser above obstacles, the player
can blast them sky-high with two onboard laser cannons. Timing is
essential though: scrolling is forced whatever the situation.
There are four sectors to navigate. As you venture further
down, indestructible forcefields and shielded weaponry will be
encountered.
In the fourth sector, dead ends are an additional hazard for the
unwary. Four lives are allowed.
Scoring is problematic. The instructions only tell you a new cruiser
is awarded every 10,000 points. Presumably it is up to you to work
out how to go about getting one. And having your score constantly
scrolling sideways at the base of the screen, together with the
title credits, doesn't help.