Deathkeep

Unlimited spells:
Press X to open the backpack. Hold LS + RS and press A, B, A, C, A. The mage and fighter-mage characters no longer need to rest to recover spells that were cast. Enter the code again to turn off this option.

View FMV sequences:
Select a character. At the Choose Difficulty menu, hold LS + RS and press P, A, C, X. All FMV sequences in the game related to the selected character will be displayed. Press P to pause the video and X to skip to the next video.

Stop time:
Press X to open the backpack. Hold LS + RS and press P, C, P, X, P. Time can be started by using this code again. When time is stopped, all monsters and other animations will be frozen. Some items, such as spells, will launch but have no effect until time is started.

All keys:
Press X to open the backpack. Hold LS + RS and press X, C, A, P. Your character will obtain a key, which will be indicated by the counter on the character bar. The key will not appear in the backpack. This code is especially useful in levels 4 and 11.

Kill all enemies:
Press X to open the backpack. Hold LS + RS and press P, A, B, A, C. All enemies on the current level will be killed.

Level skip:
Press X to open the backpack. Hold LS + RS and press C, A, B(2), A, C.

Invincibility:
Press X to open the backpack. Hold LS + RS and press C, X, P, C. Your character will now be invincible against all attacks and hazards. This code can be used again to turn immortality off.
Information in this section was contributed by Robert Yung.

Fly mode:
Press X to open the backpack. Hold LS + RS and press P, P, P, C. Your character will be have the ability to fly, as if wearing the Ring Of Flying or Winged Boots. Tap P to ascend vertically. Look up or down and move forward to ascend or descend.
Information in this section was contributed by Robert Yung.

Hints:

Secret doors
Some secret doors a left and a right vertical beam embedded in them. Others may be faint outlines on a wall.

Food
Eat rations whenever they are found, rather than storing it in the inventory. Each level contains a feast that appears as a group of mushrooms and a waterskin that will restore the food level and hit points to full. The feast also has the same effect Cure Poison spell. This should be used immediately before exiting the level. Your character will not automatically use the feast. Approach the feast and press P when "Use?" appears.

Resting
After a level is cleared, go to a rest area and restore spells and hit points. This should be done before starting the next level, where new rest areas need to be found before they can be used.

Jumping
Look down at the ground to position your character at the edge of the starting platform. Aim directly at the destination platform, holding B and using the D-pad to turn slowly if needed. Press P to start the jump, then immediately press Up, holding the D-pad as long as necessary to reach the destination platform. If the destination platform is narrow, tap Back to prevent your character from falling off the far side.

Items
The Scroll Of Hurling is a cursed item that will significantly reduce your character's food.

Game bug:
The Firebow may cause the status bar and polygons to disappear (turning the screen black in places) when fired. Move away from the location where the bow was fired to return the screen to normal.