Here are some cheats and tips for the game 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.
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.
Self destruct:
Press Start to pause game play, then press Up(2),
Down(2), Left, Right, Left, Right,
B, A, Start.
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.
Reset game:
Hold L + R + Start + Select during
game play.
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: Unknown. 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.