While in play, pause the game and enter the following code :
Up, Up, Down, Down, L, R, L, R, B, A
To delete saved data, go to the options screen, select ''EXIT'', and then hold the L, R and B buttons, then press start.
Pause the game and enter the following:
Start a new mission on stage 1 of Gradius Galaxies. Somewhere in the stage, there are 2 strips of horizontal rocks (one longer than the other). Carefully travel through the small gap in between the 2 rocks and you'll get 5000 extra points. Complete the game as normal and when you return to stage 1 again on the next loop, the stage music will change to Gradius one from NES.
To get one speed-up and full power-up of laser, options, and shield; pause and enter:
Up, Up, Down, Down, L, R, L, R, B, A, Start
This code works only once per game, including all continues.
To momentarily get the power-ups listed above, and then self-destruct, pause and enter:
Up, Up, Down, Down, Left, Right, Left, Right, B, A, Start
This code may be used as often as you like.
To unlock ''Challenge A'' just clear the game once. Then it can be selected from the main menu.
To unlock Challenge B a harder version of Challenge A, you have to clear Challenge A.