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.
Weapon Power-Up
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.
Stage Select
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.