Debug mode: 
Press L1, R2, R1, L2, Up, Down, Up, Down when the 
Namco logo flies on the screen. 


Ghost player: 
Enter the play record screen and enable that feature. Start a 
game and play as far as possible. Then, enter the gunner 
battle option and press Right(2) to select "Ghost". Start 
another game to have your self as a partner.