Enter the following at the game's pause menu to activate god mode and complete mission menu options: X, Y, X, X, Y, Y, X, Y, X, X, Y, Y.
Get Dark Campaign
First start a new game then put in your save game name. When the Episode Selection screen begins press X, Y, Y, X, X, Y, X, Y.
Get Earth Golem
Finish the Light Campaign to unlock the Golem.
Unlock Stone Gnome
To unlock the Stone Gnome as a playable character, successfully complete the Dark Campaign.
Unlock 9320 Battle Droid
To unlock the 9320 Battle Droid as a playable character, collect all of the gold in the Light Campaign.
Unlock Fetica
To unlock Fetica as a playable character, collect all of the gold in the Dark Campaign.
Level 13 (Dark Campaign): Kill the wizards
Select the Assassin with the longbow armed with maximum number of arrows. To easily kill the six wizards at the end of the mission, fire at each of them at close range. You can kill them with one well aimed power shot.
Level 13 (Light Campaign): Get to the top
Stand on the hidden floor tile to the right of staircase to disable the magic spell to reach the top.
Level 9 (Light Campaign): Free the Wizard
To free Zale, pull the lever under the stairway. Do not pull the four decoy levers or he will die.
Level 7 (Light Campaign): Lighthouse treasure
Listen to the caged Goblin near the start of the level to learn about the treasure in the lighthouse. As you leave the boat, the lighthouse is the first large building you see. Carefully follow the ledge around the base of the lighthouse until you get to a door. Enter it to get to a room with treasure and the map of Naglagard.
Level 6 (Light Campaign): Avoid rocks
At the point where four large rocks tumble down the narrow mountain path, stay on the right-hand side of the path to avoid getting hit.
Level 5 (Light Campaign): Safer route
Save the Halfling from the Orc. She will show you a safer route through the first part of the level.
Level 4 (Light Campaign): Healing
Stand in the shallow water surrounding the shining cross to heal your wounds.
Level 1 (Light Campaign): Unreachable gold
There are two pots of gold to the right of the door which is opened by the lever, high up in a cove created by a crumbling wall. Quickly press the lever, then stand on the top of the door as it rises. When the door is fully open, jump onto the ledges and up to the gold.