The Archimedes computers at school were really only good for one thing: they all had a copy of Zarch lurking somewhere. Baffled the heck out of everyone that tried it. Thankfully it turned up on the other home computers as Virus. It still baffled a lot of people, though...
The premise is simple: Alien craft are traveling the landscape, spreading a virus that's destroying the land. Your job, piloting a highly maneuverable skimmer, is to take out the invaders before the virus spreads beyond repair. Each level takes place over a relatively small map area, and clearing out the enemies takes you onto the next.
The action plays out over a colourful patchwork 3D landscape that scrolls into view as the player flies over it, and the alien seeders float low over it while their escort craft patrol the higher skies. Movement of the player craft is an extremely delicate affair, capable of rotation through all axes. Controlling it with the mouse requires a great deal of skill and patience, so it's lucky that there's also a keyboard control option. The difficulty of the controls brought the game under harsh criticism at the time, and it's true that they aren't the easiest to get to grips with.
Despite the plentiful accidental crashes though, Virus remains a beguiling game. I love the strange atmosphere brought on by the visuals and the graceful movement of the craft. Just flying low over the landscape at speed is great fun. It's a game that's worth trying to master.