Code Effect

Pause the game, hold L1 and press Triangle, R1, Triangle, Square, R1, Circle, Square, Square then release R1 All Weapons

Hold L2 and press Circle, circle, Square, Triangle, R1, Square, Triangle, Circle, then release L2

Pause the game and enter the following codes:

All Weapons:-  Hold L1 and press Triangle, R1, Triangle, Square, R1, Circle, Square, Square. 

Level Skip:-  Hold L2 and press Circle, Circle, Square, Triangle, R1, Square, Triangle, Circle.

Gameshark codes

Unlimited ammunition:
80059A64 0063 
Unlimited armor:
80019DD2 00C8 
Unlimited energy:
801080F8 000F 
Heartbeat high:
800B7EB4 017F 
Heartbeat low:
80019DD4 0001 
Red key:
800B8234 0003 
Green key:
800519C2 0001 
Blue key:
800519C4 0001 
Yellow key:
800519C6 0001 
Purple key:
800519C8 0001 
Light Blue key:
800519CA 0001