Note: There are 20 basic levels in the game. Level 21 is a repeat of level 1, but
with UFOs instead of jets to shoot down. The password at level 22 is the same as
level 2. You must enter the password for level 20 or 21 and play the game from
there to get UFOs instead of MIGs. Entering level 21 in Ace mode gets you started
all over again from level 1, but with World War I era tri-planes instead of jets
or UFOs.
Flying cars:
It is possible to replace the jets with flying classic cars. Something can be
done in novice mode at level 6 that will result in a constant tone until you get
to level 7. Level 7 will then start with classic cars flying at you instead of
jets. The level passwords with the cars are identical to those with jets. You
must duplicate some sort of game condition (complete all the first six levels
with no damage? Complete level 6 with no damage and using only one plane?) to
unlock the cars. Please submit more information regarding this bonus.
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