Chainsaw:

To unlock this hidden weapon, pause the game and input the following code: Up, Down, Up, Down, Left, Right, Left, Right, Circle, Square, Circle, Square.

Baby Rattle:

To unlock this hidden weapon, firstly beat the game on the easy difficulty setting. Next, pause a new game and input the following code: Left(2), Right(2), Circle, Square, Square, Circle, Up, Down.

Telephone:

To unlock this hidden weapon, firstly beat the game on the Normal difficulty setting. Next, pause the game and input the following code: Right, Left, Right, Left, Down(2), Up(2), Circle, Square, Circle(2), Square(2).

Swordfish:

To unlock this hidden weapon, firstly beat the game on the Hard difficulty setting. Next, pause the game and input the following code: Up(2), Down(2), Left, Right, Left, Right, Circle, Square, Circle, Square.

Video Gallery:

Beat the game on any difficulty setting.

Voice Credits:

Play through the game until getting to the large courtyard just 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.

Sand Gate Rewards:

Deactivate the following number of Sand Gates to unlock a special reward.

1 Sand Gate – Fourth Sand Tank
2 Sand Gates – 100 Sand Credits
3 Sand Gates – Eye Of The Storm Time Power
4 Sand Gates – Fifth Sand Tank
5 Sand Gates – 150 Sand Credits
6 Sand Gates – Winds Of Sand Attack
7 Sand Gates – Sixth Sand Tank
8 Sand Gates – 200 Sand Credits
9 Sand Gates – 9 Sand Attacks