Press start while playing and enter these codes at the password option using the C button.

Password - Effect
DCKMT - Full upgrades
VRYLTTL - All spells with cost of no manna
NSCRN - show entire map
GLTTRNG - 10,000 gold 5,000 lumber and oil
MKTS - Fast building and upgrades
NGLS - Disable magic traps
NVRWNNR - Removes victor sequence and lets you keep on playing
TSGDDYTD - Greater strength and invincibility except against magic