All weapons
Enter "NSRLS" as a password.

Maximum ammunition
Enter "MMLVSRM" as a password.

Play as General Plastro
Enter "PLSTRLVSVG" as a password.

Play as Vikki
Enter "GRNGRLRX" as a password.

Play as Tin Soldier
Enter "TNSLDRS" as a password. Note: Enter this code after activating another character code to create a Tin version of that character.

Test information
Enter "THDTST" as a password.

Mini mode
Enter "DRVLLVSMM" as a password.

Reverse weapon selection
While playing the game, hold B and press Z to cycle through weapons in reverse order.

Restart level
While playing the game, hold L + R + C-Down to return to the starting location of the current level.