For all weapons, enter the password F1SH1NGFORGVNS.

For invulnerability to all damage, enter the password FVNKYG1BB0N. Be warned, though: you can still be trapped in places where you'd normally die. My advice? Save early, save often.

Get into the carnage quicker with this code. At the password screen, enter FLYTO followed by the level you desire. (eg., FLYTO14 for level 14.)

For unlimited firepower, enter the password F1LLMYPOCK1TS.