At the Password screen enter ??HOST???. The cheat menu should now be enabled...
Enter INVINCIBLE as a password.
Enable all exits:
Enter NO_MISSION as a password.
Enter **URANUS** as a password
Unlimited weapon upgrades:
Enter 2UNLIMITED as a password.
View ending sequence:
Enter **SATURN** as a password.
Enter SHOWCREDIT as a password.
Alternate opening sequence:
Enter SHOWDROIDS as a password.
Kill opponents with single shot:
Enter GRIMREAPER as a password.
Enter LAZYPLAYER as a password.
Fight Bosses only:
Enter GET_SACKED as a password.
Thanks to Revolution readers Andrew Snook, Manuel Quiles, and, uh, God!