Various Cheats:
During gameplay press ENTER then enter a code below
say uncle - finish mission
eat your spinach - Invincibility

Edit Game Variables:
Open the "player.ini", "player airplanes.ini" and "player guns.ini" files.

In the "player.ini" file, find all the "rof" (rate of fire) entries and
alter them from "3.5" to "35".

In the "player airplanes.ini" file, alter all of the health entries by adding
a few of zeros. Reduce the health values for the enemy planes and enemy boats.