Secret telephone weapon:
Successfully complete the game under the normal difficulty setting. Take out your dagger and do not have any secondary weapon. Pause game play, then press [Right] [Left] [Right] [Left] [Down] [Down] [Up] [Up] [Up] [Down] [Up] [Up] [Down] [Down].

Secret swordfish weapon:
Successfully complete the game under the hard difficulty setting. Take out your dagger and do not have any secondary weapon. Pause game play, then press [Up] [Down] [Up] [Down] [Left] [Right] [Left] [Right] [Up] [Down] [Up] [Down].

Secret chainsaw weapon:
Take out your dagger and do not have any secondary weapon. Pause game play, then press [Up] [Up] [Down] [Down] [Left] [Right] [Left] [Right] [Up] [Down] [Up] [Down].

Easter Egg - Voice credits:
Play through the game until getting to the large courtyard just immediately before the first chariot sequence, during your second Dark Prince transformation. Look in the corner of the courtyard to find a hole in the ceiling which enemies appear from until you leave the area. Stab and hang from the panel near that hole to open the exit. Climb the pole nearest to the hole in the ceiling to hear a monotone female voice announce the game's voice credits.