Advance Campaign Mode - First complete Campaign mode, enter the Battle Maps screen buying the "Advance Campaign" option for a coin. Hold the select button and choose Campaign mode to start an advanced campaign with a more difficult computer opponent. Deleted Saved Games - Hold L, R and Select when turning on your Game Boy Advance. Field Training Bonuses - First finish Field Training mode to unlock War Room, Campaign, Design Maps, Stats and Special Intel options. Ghost Mode - Hold B during your turn. In-game reset - Press Start, Select, B and A together during gameplay. However do not use this while the Game Boy Advance is linked to a Gamecube or it may cause loss of data. Quickly Finish Field Training - Select the final battle of Field Training mode. Win the battle to unlock the options that you normally need Field Training to be completed to unlock.