Ending sequence
Enter "HOUSE" for the password and then in any level, get the numbers to "9" and the letters to "CCP". Then, hold [R1] + [R2] to view the ending sequence and the game's credits.

Invisibility
Enable the "Level and room select" code, then advance to the ending sequence. Wait until the credits complete, then advance through the level names two times until you get to the house. When you reach the house, you will be invisible.

Invincibility
Enter "INFIN" as a password.

Unlimited ammunition
Enter "JUICY" as a password.

Level and room select
Enter "HOUSE" as a password and begin game play. Press [R1] during game play to select a new level or [R2] to choose a room. Alternatively, hold [L1] and press [Select] during game play to choose a level or [R2] to choose a room.

Note: The levels are abbreviated as follows at the level selection screen.

Castle levels: CS<number>
Aztec Temple: AZ<number>
Atlantis: AT<number>
Ship: SH<number>
Western: WS<number>
Corridors Of Time: 5BU and ABU
Game over sequences: GOV
Home: LHL and LST
Credits: CRD
Ending sequence: CCP