Cheat Codes:
To enter the codes below you must watch the entire opening cinema. When the title screen
appears, hold L1 + L2 + R1 + R2 and press Select. The words "PUSH START" will change to
"SECRET CODE" with two letters behind it. From here you can use Up and Down to change the
first letter, or Triangle, and X to change the second. 

Debug Mode: 
Enable cheat codes, then set the code to MA and press Select. Change the code to SV and press
Start. The following commands must be entered using Controller Two: 

Code - Effect
Up - Boosts weapon power to maximum for 10 seconds
Down - Toggles voice mode
Left - Change gunlock type
Right - Skip area and disable invincibility
Triangle - Toggles invincibility
Circle - Increases bombs
Square - Change weapon type
X - Increases weapon power-up time by 30 seconds

Level Select: 
To use these codes follow the directions for the "Cheat Codes" trick above. 

Level - Code
2 - MA
3 - UT
4 - RH
5 - MK
6 - HT

Special Codes:
To use these codes follow the directions for the "Cheat Codes" trick above. 

Code - Effect
QB - Makes player large
CM - Makes player small
MV - Display smaller buttons by pressing any button on Controller Two
SS - Ceapon power-up time starts at 999 seconds
YI - Start with nine bombs
TY - One hit kills player