Gradius 3

Arcade mode:
Enter the option menu from the title screen. Highlight the "Game Level" selection and rapidly tap A until the "Game Level" text changes to "Arcade". Press Start(2), to begin an arcade mode game.

Random weapons:
Select a game mode from the option screen, then press Start to enter the weapon selection screen. Press R to enter the edit mode. Press X, Y, X(2), Y(2), X, Y for a random selection.

Extended demonstration mode:
Hold A button at the title screen. The demonstration mode will continue until reaching the Boss.

Twenty-nine lives:
Hold Left and press A(3) at the title screen. Then, press Start to begin game play.

Extra credits:
Rapidly tap X at the title screen until the total number of credits approaches eight. Press Start to begin the game before the title screen disappears.

Start with up to nine credits:
Note: This trick requires a controller with a auto-fire feature. Put the L, X, and Y buttons on auto-fire at the screen with the "Options", "1 Player", and "2 Player" selections. If done correctly, the number of credits should increase from 4 to 9.

Instant power-up:
Press Start to pause game play, then press Up(2), Down(2), L, R, L, R, B, A. Press Start to resume game play. Your ship will gain missiles, force field, all options, and more speed. Note: This code may only be used once per level at first.

Note: If this code is activated on a later level, you will be able to use it more times. For example, if you use the code on level 4 and die, you can use it about three or four more times.

Self destruct:
Press Start to pause game play, then press Up(2), Down(2), Left, Right, Left, Right, B, A, Start.

In-game reset:
Hold L + R + Start, then press Select.

Increased R Option:
Select the "R Option" (rotating options) selection from the weapons panel. Obtain all four Options, then collect enough power-ups to highlight the "Option" selection again at the bottom of the screen. Hold A to increase the radius of the R Options.

Spread Options:
Activate the F-Option or R-Option. Collect power-ups until that specific option is highlighted. Then, hold A.

Reset game:
Hold L + R + Start + Select during game play.

Hint: Bonus stages:
Levels 2, 3, 4, 5, and 7 contain a bonus stage. These require that some sort of condition be met and are entered by flying into a hidden area.

Level 2
Condition: None. Fly into the first ship opening along the bottom of the screen. It is located in the last section of the stage (after the giant carbonated bubbles) before meeting the Boss

Level 3
Condition: Destroy all of the guns on the ground. Fly close to the low rock ceiling toward the end of the level and immediately before the last "mountain".

Level 4
Condition: No power-up boxes at the bottom of the screen may be lit. Fly into the back of the Moai head located in the middle of upright three heads toward the end of the level. This particular head will be facing away from you.

Level 5
Condition: To get in, the hundreds digit of your score must be 3, 5, or 7. Fly through the fire at the corner of the inverted volcano. It is located just before the small passage that leads to the two-headed fire dragon.

Level 7
Condition: Unknown. Fly through low corner just after the four turrets. Your ship would normally have to fly upwards diagonally at this point. Note: Collecting a lot of power-up modules by destroying turrets allows entry into the secret level area. The weapons select bar was on an empty box each time - missiles then lasers.