Panzer General 2 Codes -

Unlimited prestige points:
Clear a city of enemy units and place one of your units within that city. Cancel the moving your units into the city to keep the prestige points earned. Repeat this procedure to gain an unlimited amount of prestige points. Note: This will only occur if the difficulty is over 100%.

Play both sides:
Select to play by email at main menu. Save the game, then load it again. You can now play as both sides.