Trivia
The first Amiga disk (from the Activision release) contains the following message from the authors of the game to all potential crackers:
Hello Hacker, before you start ripping into this game please remember that you are destroying the Amiga and the jobs that are associated with it. We've spent over a year on this product and obviously want to make loads of money so if you do crack it (very easily, its THAT easy protection) then don't release it, Thank You.
The Commodore 64 version is bugged - seeing another plane in it is a rare occurrence.