Hold L and R and enter these cheats during game play:

God mode: RIGHT, LEFT, RIGHT, LEFT, UP, DOWN, UP, DOWN
Damage times 100: UP, DOWN, UP, DOWN, LEFT, RIGHT, LEFT, RIGHT
Enemy attacks pass through Bard: LEFT, RIGHT, LEFT, RIGHT, UP, DOWN, UP, DOWN
Full health and mana: LEFT, LEFT, RIGHT, RIGHT, UP, DOWN, UP, DOWN
Silver pieces and Adderstones: UP, UP, DOWN, DOWN, LEFT, RIGHT, LEFT, RIGHT