Invincibility
     Pause gameplay and press Square, Circle, L1, R1.

All Weapons with Full Ammo
     Pause gameplay and press Square, Circle, R1. L1.

Tin Foil Uniform
     Enter the code 'TNMN'.

Level Passwords
2 Bridge - FLLNGDWN
3 Fridge - GTMLK
4 Freezer - CHLLBB 
5 Inside Wall - CLSNGN 
6 Graveyard - DGTHS 
7 Castle - FRNKNSTN 
8 Tan Base - BDBZ 
9 Revenge - LBBCK 
10 Desk - DSKJB 
11 Bed - GTSLP 
12 Blue Town - SMLLVLL 
13 Cashier - CHRGT 
14 Train - NTBRT 
15 Rockets - RDGLR 
16 Pool Table - FSTNLS 
17 Pinball Table - WHSWZRD