Chester Field: Ankoku Shin e no Chousen

The invincibility code is to be entered on the menu screen, which is accessed by press Select during gameplay.

During gameplay, press A and B on Player 2's controller to enable the debug mode. You can press Up/Down on Player 2's controller to enable/disable invulnerability. You can press Up on Player 1's controller to enable the Morning Star weapon. Pressing Select on Player 1's controller allows you to select a stage with Left/Right, then Start to go to it. Pressing A and B allows you exit the debug menu with the changed parameters.

The subscreen in Chester Field causes a number of effects to happen - either by making key objects disappear or by moving a character/enemy.

-Bringing up the subscreen removes all enemy-dropped items and all projectiles from the screen. If you know you are about to be hit, this can save you a few hp.

-Bring up the subscreen when a stationary enemy is onscreen. When you return to the game they will have been moved. If a stationary enemy is in your way, this can be used to make some room.

-The big part of this glitch allows you to fall through the middle-divider floor in the dungeon maze areas of each stage. Normally, you have to find a ladder to drop down but this glitch eliminates the need (and makes some of the mazes passable much more quickly).

What you do is duck on top of the middle floor of the room. Bring up the subscreen, then return to the game. Your legs should be stuck in the floor. If you move left or right, you will fall down to the lower level. You can abort the glitch by jumping from inside the floor. You cannot fall through to another room - you will just get stuck in the bottom floor if you try that (jump out in this instance).