Hudson's Adventure Island II (NES)

Hudson's Adventure Island II is a NES game by Hudson Soft, with arguably one of the fullest-featured debug menus ever seen in a commercially-released NES game.

World Select
To access this level select menu, on the title screen, press Right, Left, Right, Left, A, B, A, B.

Press Up or Down to select a world, and press A to start the game.

Debug Menu
To access the debug menu, change ROM file address to  (or use the Game Genie code ), then enter the World Select code shown above.

Scene Select Mode


This is the first screen you'll see after entering the code. Press Up or Down to change the first digit of the current value, and Left or Right to change the second one. Press A to move the cursor between SCENE NO (level number) and DEBUG FL (described below). Press Start to begin the selected level. Note that you'll be returned to the menu after the level ends.

World Select Mode


Press B to switch to World Select mode. This is the same as Scene Select mode, except you start at the beginning of the selected world, and aren't returned to the menu after clearing it. Oh, and the background's blue, too.

In-Game Debugging Features
Setting DEBUG FL to any odd value (e.g., ) will enable the following features in-game:


 * One of every dinosaur and a hammer in your inventory (only in Scene Select mode)
 * Complete invincibility (except to rocks, which still take off energy but don't kill you)
 * Immunity to zero energy death
 * Immunity to pits (you reappear at the top of the screen)
 * Free-movement mode (press Start to pause, then use the D-pad to move around the level; the 0 indicates your current location)
 * Show hidden eggs (locations are marked with score sprites; the value changes depending on the contents of the egg)

Using controller 2:
 * While paused with Select, pressing A will advance the game by 1 frame
 * Pressing B will cycle through the various things Master Higgins can ride:
 * Nothing
 * Skateboard (even if you don't have a hammer)
 * Blue Camptosaurus
 * Red Camptosaurus
 * Pteranodon (flying dinosaur)
 * Elasmosaurus (water dinosaur)
 * Pausing and pressing A switches to Palette Editing mode. On controller 1:
 * A: Cycle palette (0-3: BG; 4-7: Sprite)
 * B: Cycle selected color
 * Up/Down: Increase/Decrease selected color by 10
 * Left/Right: Increase/Decrease selected color by 1

Pressing Start unpauses the game, leaving any modified palettes...modified. There does not seem to be a way to modify the overall background color, however.

Setting DEBUG FL to will enable a demo-recording mode. As soon as you enter a level, the score and energy meter will be replaced with the high score (as normally seen during demo playback), and all keypresses will be recorded to SRAM beginning at. Unfortunately, there doesn't seem to be any code that actually reads this data once it's written.

Test Mode


While in the debug system's World or Scene Select Mode, press Select to change to Test Mode and back.

Press A to choose an option, and press Start to return to this menu (for the first 3 options).

OBJ (Object viewer)
is the object number, seems to be another selector of some kind.


 * Up/Down: Change by 10
 * Left/Right: Change by 1
 * A/B: Increment/Decrement by 1

CHA (Character ROM viewer)
Displays graphics from the game's CHR-ROM. There is no way to change the palette, however.

This also allows you to alternate between 8x8 and 8x16 display modes, the latter being used for sprites.


 * Left/Right: Change displayed page
 * Select: Change between 8x8 and 8x16 display mode

SOUND (Sound test)
Just a quick 'n' simple sound test mode.

Songs are 40-5A.


 * Up/Down: Change sound number by 10
 * Left/Right: Change sound number by 1
 * A: Start playing music
 * B: Stop playing

ENDING (Ending sequence)
This takes you straight to the... ending sequence, surprisingly enough.

It automatically follows up with the credits, so it's likely the next option was added by a frustrated programmer just to speed up the process a little.

STAFF (Credits)
And here's the credits screen. After the credits play through, the game goes into an infinite loop, just like if you beat the game normally. Nothing to see here, folks.

WARP (Warp room test)
This option acts as if you got the secret warp in the first island. If you say No, you'll even start off where you would if you hadn't accessed it via this menu.

ITEM (Item room test)
Much like the warp test, this one places you in a secret item room from the first world's boss level. You can either beat the boss (to go to the next world) or die in the level (and go off the screen in the first world).

Unused Demo
Although the game contains recorded input for five demos, only four are actually shown (levels, , , and ), and the table of level numbers is in fact only four entries long. The fifth demo seems to correspond to level and may be unfinished, as Master Higgins simply comes to a stop and dies at the end (every other demo ends with him either falling in a pit or colliding with an enemy). The Game Genie code will reenable this lost demo.