Codes:

50% more armour : pcpnl
Invulnerability : cpplm
quad damage codeID : 7148 : bdgfk

Level skip
Enter "GZXCV" as a password.

Infinite attempts
Enter "KPLYO" as a password.

Invincibility
Enter "CPPLM" as a password.

Infinite ammunition
Enter "FCQWH" as a password.

Infinite chaingun
Enter "ZWDRM" as a password.

Infinite rockets
Enter "JLWLD" as a password.

Infinite missiles
Enter "MGMWS" as a password.
Infinite wingtips

Enter "RFRBC" as a password.

Armor increased 50%
Enter "PCPNL" as a password.

Quadruple damage
Enter "BDGFK" as a password.

Double miles per gallon
Enter "LLMMN" as a password.

Infinite fuel
Enter "DRWCV" as a password.

Full map
Enter "BNBMP" as a password.

Stealth mode
Enter "JYMNT" as a password. Note: Weapons will be disabled in this mode.

Debug menu
Enter "HLNRU" as a password.

Agility
Enter "GLCND" as a password.

Overhead view
Enter "BGRZP" as a password.