1. Save a campaign or war room level and turn off game.
2. Go to field training and select naval battles. Make sure to lose in naval battles by letting your t copter get destroyed.
3. Then go to design maps mode. Make an HQ and an infantry then destroy the infantry. your screen will be glitched.
4. Press A on a piece of land click down 3 times where you are and press on options.
5. Then click down 2 times to exit map. Say yes.
6. You will be at the main menu screen. Then go to war room or campaign. Click L and you should be able to put anything in you want in the map. Once your done save. Then turn off you gameboy. When you turn it back on the glitch will be gone but whatever you put on the battlefield will still be there. You can easily beat the game!