”Xenocide has a basic premise: kill the aliens that have infested the moons of the planet Talos IV before they spread to the surface of the planet. The logical way to do this? Completely destroy the orbiting moons! How to do this? You must first travel to the surface of the planet in a hovering assault craft (don't let the aliens mess up your windshield!) shooting aliens and dodging rocks along the way. You must also pick up canisters, which are very important, because they are what you will store your ammunition in for the following levels.

To control it, use the keypad or joystick with open apple (command key) being the fire button and option being the missile launcher and space throwing off a nuclear bomb which will destroy any aliens ahead of you.

Assuming you haven't been blown up, or run out of fuel by the time you reach the outpost station you'll then proceed to the second level of a planet. The game now takes the 3rd-person view of the classic side shooter. The object in this level is to collect five bombs located throughout and get to the next level. The fire button shoots lasers. Option shoots grenades. Along the way, you will find pulsating spheres – these will allow you to toggle between the options given in the lower middle right of the screen to increase fire power or recharge shields. Space bar selects what it's currently toggled to. Keep an eye on the fuel gauge!

The next level is very similar to the last, except that you're now underwater, need to keep an eye on your oxygen, and have to find keys instead of bombs. The 4th part of the game comes in a top down view like

Gauntlet

Having different modes of gameplay is something of a rarity these days mainly because game developers are interested in releasing something that doesn't require a lot of effort to produce. Different modes of play increase the challenge and make the game take longer to master, which IS a good thing! ;-)”