Haunted Mansion

Invincibility:
Hold Right, then press Square, Circle, Circle, Circle, Square,
Circle, Triangle, X during game play.

Weapon upgrade:
Hold Right, then press Square, Square, Triangle, Triangle, Circle,
Circle, Circle, X during game play.

Stage select:
Hold Right, then press Circle, Circle, Square, Triangle, Triangle,
Square, Circle, X.

Level - Password

Level 2 - Ox, Horse, Tiger, Sheep
Level 3 - Rooster, Boar, Rabbit, Dragon
Level 4 - Rat, Dog, Monkey, Snake
Level 5 - Sheep, Tiger, Horse, Ox
Level 6 - Dragon, Rabbit, Boar, Rooster
Level 7 - Snake, Monkey, Dog, Rat

Zeke is a skeleton:
Hold X + Circle + A + Triangle at the opening sequence, before the legal screen.
Release the buttons at the title screen.

Zeke is invisible:
Hold X + Square + L1 + R1 at the opening sequence, before the legal screen.
Release the buttons at the title screen.

Health Restoration
Save and quit your game. Then load back your saved game, and you'll
begin at the save point with maximum health.