xcept from "Virus" (or rather "Zeewolf 0") and Space Invaders, I can't really think of any."
Wasnt Zewolf a helicopter game on the amiga?
Theres:
-Virus by david braben (of elite fame), (this was a cool game) http://en.wikipedia.org/wiki/Virus_(computer_game)
-Virus and Virus2 (a kind of shareware puzzler): http://www.arcadetown.com/virus2/index.asp
-Virus a modern looking FPS thingy : http://www.gamespot.com/pc/action/virusthegame/index.html
For a start.
then theres:
Space invaders, super space invaders, spectrum invaders, Psion invaders, Chicken invaders, Space invader typing trainer, hyperspace invaders....
How did they get away with it?