Takahashi Meijin no Boukenjima IV

Takahashi Meijin no Boukenjima IV is a Famicom (NES) game by Hudson Soft, never released outside of Japan. This entry in the series takes a much different, non-linear approach compared to the previous three titles, requiring you to seek out various items and abilities in order to access new areas. It also does away with the old "hunger meter," opting to use a standard life bar instead (and there was much rejoicing).

Test Mode
The game contains a debug menu very similar to that of Hudson's Adventure Island II. To activate it, use the Game Genie code (or change ROM address  to ), then choose PASSWORD on the title screen.

The menu options are pretty straightforward. The two DEMO options allow you to record and play back your own demo, like the one shown after the title screen, although it's erased when you unload the ROM (unless you set the "battery-backed SRAM" bit in the ROM header).

Unused Debug Text
Beginning at ROM address is a series of unused text strings:

OPENING ADVENTURE ISLAND 4 START--MAIN SELECT-TEST VER 10-18 PRINT TEST DATA 80 PRINT TEST DATA 81

Presumably, OPENING would have been displayed in place of the game's intro during development, while ADVENTURE ISLAND 4, START--MAIN, SELECT-TEST would have been displayed in place of the title screen. The two PRINT TEST DATA strings are a complete mystery.

Interestingly enough, 10-18 is actually written to the bottom-right corner of the screen shortly after reset, but is immediately overwritten with the intro background. This is the only time the text drawing routine associated with these strings is ever called!