OC HIGH / STUDENT NEWS AND VIEWS : video game review : CD Shooters : <i> Microcosm by Psygnosis ($55-$60); Tomcat Alley by Sega ($59.99) </i>

For the serious, hard-core gamer, it’s becoming more and more obvious that some sort of CD drive is a vital part of the video game experience.

Although I’ve been critical of the Sega CD in the past, dramatic improvements in game quality have me close to eating my words, and two new games are adding to my dining pleasure.

The first is Microcosm, a strange and unusual disk from Psygnosis.

The plot is long and complicated; 20 pages of the instruction manual are gobbled up telling the tale. Basically, you’re a top agent for Cybertech, reduced to the size of a dust mite and inserted, along with various vehicles and weapons, into the body of Cybertech president Tiron Korsby.

You travel though Korsby’s body, trying to find and destroy a manipulation device--Grey M--buried deep in his brain by the leader of a rival company.

Traveling through veins and arteries, you fire on both natural viruses and the artificial probes filling his body to defend the intruding device. Your course is predetermined, although you can maneuver your craft along the preset path.

You use three mechanical aids on your journey. A Spook Series 4 pod is your first vehicle. It’s used in two sections of the game; the initial battles, in the cephalic vein, and the third stage, the superior vena cava and the heart.

Your second vehicle is the Hunter Killer RS-18. You use it in section 2, the left lung, and section 4, the carotid artery.

When you reach the brain, section 5, you are stuffed into the S2-21 pressure suit for close-up work.

Each has a variety of weapons, including lasers, cannons and smart bombs, which are upgraded by icons floating throughout the body. You’ll need the firepower, because the variety of natural and artificial weaponry is awesome.

As are the graphics. And the dramatic soundtrack, created by former Yes keyboard player Rick Wakeman. And the control, which is smooth and fluid.

This is a continually fascinating and entertaining game, devilishly hard to beat. It’s Sega-rated MA-13, with parental discretion advised.

*

Sega is responsible for the second CD--Tomcat Alley.

In this classic battle for air superiority, you are the radar and missile officer aboard an F-14 Tomcat fighter-bomber. You and your companions are trying to wipe out two MIG squadrons stolen by renegade Russian Col. Alexi Povich and relocated to the Mexican desert.

Tomcat Alley gives you a from-the-cockpit view of the action as you punch in waypoint coordinates, trigger flares and chaff to throw off enemy missiles, handle the radio and recon camera and line up shots at waves of MIGs and SAM batteries defending Povich’s headquarters and his chemical warfare threat.

Tomcat Alley isn’t a true flight simulator, since you don’t fly the plane. The direction pad is used to line up the cross hairs for missile shots at enemy planes and to direct bombs and missiles against ground targets.

But the action is hot and heavy, and the CD, rated MA-13, is crammed with variations, so you almost never fight the same fight twice in a row. There are excellent, if slightly fuzzy, film sections with live actors, solid sound effects and great shots of exploding jets--MIGs, if you shoot well; your own, if you miss.

Tomcat Alley missions become more and more complex the closer you get to wiping out Povich and his pals. But keep trying. You might get a medal.