Additional Ammunition
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit one of the "level_*" files in the game folder. Locate the "//Bullets, Projectiles, Missiles" section and increase the three numbers that follow the "Ammo" entry that is underneath to set the amount of bullets, projectiles, and missiles (in that order) that will be available in that level.
Change enemy aggression
Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit one of the "level_*" files in the game folder. Locate the "//Tank, Jet, HelicopterGun, HelicopterRocket" section and decrease the four numbers following the "Aggression" entry to lower how difficult the enemy tanks, jets, helicopter guns, and helicopter rockets (in that order) will be in that level. Note: The numbers must be from 1 through 9.