All weapons and craw unit:
Pause game play and press Up, Right, A, Down, Right, A, C, Left, Up, B, Up, Right.

EX options:
Complete the game without using any continues under any difficulty level to see a longer bonus ending. Note: the last Boss will be more challenging when this is accomplished. Hold L + R and press Start at the options screen to access the EX options.

Extra continues:
Enter the options screen and leave the Saturn at this point for three hours to get one additional continue. A total of ninety-nine continues can be accumulated by this method.

Free play mode:
Complete the game with the good ending by quickly destroying the Boss in level 7 when he changes into his third form, before getting the high speed bonus. This will unlock a free play mode that allows the game to be played with unlimited continues.

Hidden images:
Insert the game disc into a PC compatible CD-ROM drive and look in the "Omake" directory for several bitmap graphic image files.