Moonbase Io

This isn't an either/or game-it uses both a minifloppy diskette and a cassette tape. The disk holds the game play, graphics, special effects, etc. The cassette gives you a very good sound track with voices from Earth controllers, mechanical robot speech, and even a thank-you message from the President, by deep-space radio, of course. The tape also controls parts of the game play.
You are the pilot of a heavily-armed Jupiter probe that has to defend Earth's bases on lo, Europa and Ganymede-three of Jupiter's moons-from hordes of alien attackers. First you have to get through a mine field that the aliens have spread around the moons and dock with the orbiting Earth base at Io. Then, after refueling, you fight off wave after wave of enemy attackers in one of the most exciting and fast-paced space shoot-outs I've seen in video games anywhere.
If you survive all that, you fly to Europa for a repeat performance: mine field, docking, waves of attackers. Then on to Ganymede for more of the same. Once through these six exercises, you have to go after the alien mother ship, which is a job and a half.
This game is not only innovative and loaded with - tension-it'll take an awful lot of practice to get through the entire scenario with your laser cannons intact. The graphics are excellent, the sound track adds an extra touch of realism, and you'll have to fight off your friends to get control of your joystick back.
But I do wish it had a repeat practice track on the tape to help sharpen space shooting skills. You have to rewind the tape and start over each time you lose your ship. You do get an, extra ship for each wave of attackers you get through, but it could really use a neophyte practice level.
Don't try to blast all the mines. Blast the ones in your path so you con get to the satellite station safely. On the moon, don't try to be a hero.