During the game, call up the "bomb parts" screen by pressing option 2 when not standing next to a monitor. Next, press up, right, up, left, down; you'll hear a buzzing signal to indicate that you've triggered the game's invincible mode. Preform the trick again if you want to turn off the invincible mode.
During the game, call up the weapon screen by pressing option 2 twice when not standing next to a monitor. Press down, down, down, down, right, up, option 2; you'll get a full supply of every weapon. Repeat the code when you need a weapon recharge.
View the map screen by pressing option 2 while standing next to a monitor. Next, press down, up, up, up, up, up, right; you'll hear a buzzing signal to confirm the code.Now you can pick a level by pressing up or down on the directional pad; the number in the lower-right corner of the screen shows which stage you've picked. Pressing up and down also toggles the score between "00000"and "00128"; "00000" puts you at the beginning of the chosen stage, and "00128" takes you to the end of the stage. When you've finished setting the stage numbers, press option 2 to warp there.