The horizontally scrolling shoot-outs have achieved enduring popularity among electronic gamers primarily because they offer such varied play possibilities. Players seem to adore the experience of zooming over constantly changing terrain, plunking the helpless from the jaws of death and blasting the enemy ships right out of the sky. As a result, examples of this genre such as Defender, Stargate, Chopper Command, The Empire Strikes Back, Space Jockey, Scramble and Protector II rate very highly among players in every format from coin-op to stand-alone.

One of Planet Patrol's most unusual features - unique at the time this is being written, in fact - is that the action goes from right to left. The arcader uses the joystick to guide an on-screen craft, which casts a shadow on the ground as it flies overhead, through a series of challenging adventures.

The first phase of the mission is a doubleheader. Your ship must do battle with a fleet of alien invaders which is nestled within a deadly asteroid field. The pilot must destroy the enemy force while carefully avoiding collisions with the space rocks. When this task is accomplished, the player's ship must rendez-vous with a pilot who is stranded in space.

The second part of the mission is pure avoidance. The arcader must blow up three horizontally stacked fuel depots. The explosion carries the debris across the entire playfield. The program then hurls the ship through the shrapnel at double speed while the pilot tries to steer a safe path through the danger.

Another docking sequence follows this phase. Here, the gamer must refuel and dock with another stranded pilot who needs to be rescued. Although it at first appears to be a replay of the opening phase, first-time players will begin to wonder about their eyesight. There's nothing wrong with the old peepers, however: it's simply the onset of night. Slowly, darkness creeps over the playfield, turning the planet's bright red sun into a crescent moon.

The only way to light your way to the finish of this scenario is to fire off a round. The blast illuminates the entire screen for an instant. Strategically, therefore, the play should keep the ship hugging either the top or bottom of the playfield, firing almost constantly while ducking asteroids and hitting enemy spacecraft.

But watch that itchy trigger finger! You don't want to forget that poor stranded fellow-pilot. Accidentally icing the guy you're supposed to rescue will cause this scenario to begin all over again.

The sound and graphics are not the most sophisticated available, but there is so much happening in this game that you won't have a lot of time to dwell on the fact. This is quite an impressive bow from Spectravision and Planet Patrol bodes very well for games to come.