If you goto Open Fodder, you can download an open source port of Cannon Fodder. It contains all the demo and special versions that were released. If you want to play Cannon Fodder the full game, you need to supply the PC or Amiga data files.
Great game, although I had to be content with the Atari ST version. I also remember a special edition for an Amiga cover disc which featured the Cannon Fodder guys invading a sensible soccer pitch.