Gameboy Advance | Gamecube | PC | Playstation 2 | Xbox | Playstation | N-Gage

Using cheat mode:)
Remember to create a backup copy of a file before you begin to edit/alter that particular file with a text editor. Using your text editor alter the "default.kmp" file in the game directory. Add the following lines below the "[Cheat Commands]" heading:

alt+shift+a = toggle_avatar_invulnerable
alt+shift+b = pass_one_hour
alt+shift+c = unpass_one_hour
alt+shift+d = sunrise_sunset
alt+shift+e = pass_one_minute
alt+shift+f = unpass_one_minute
alt+shift+g = toggle_sun
alt+shift+h = toggle_wind
alt+shift+i = toggle_storms
alt+shift+j = toggle_avatar_fast
alt+shift+k = toggle_avatar_fly

Now push one of the keys below while playing the game to enable that particular cheat code.
 

Additional codes:
The codes below need v1.07 of the game, and may be bound to any desired key combination in the "default.kmp" file as described above.

recharge_mana
fill_spellbook
spells_0-2
spells_3-5
spells_6-8

Hidden teleporters:
Find the fence without a gate behind the Avatar's house. Climb on the nearby training dummy and jump over the fence. Find the level hidden near a bush by the large tree. Pull the lever to find teleporters that will equip your character with armor and allow travel to various places in Britannia. REMEMBER: You can not return by teleporter once you leave.

Invisible to monsters:
Push B to open your backpack and attack monsters. They will ignore you as long as the backpack remains open.