インスマウスの館 (commonly known as Insmouse No Yakata or Innsmouth No Yakata, meaning Innsmouth Mansion or Mansion of Innsmouth) is a video game for the Virtual Boy developed by Be-Top and released by I'Max on . It is loosely based on H. P. Lovecraft's The Shadow Over Innsmouth, or, reportedly, a Japanese film (possibly インスマスを覆う影) based on the same story.
This page is an attempt to collect everything that is known about the game.
Planet Virtual Boy has scans of the original manual in Japanese as well as an unofficial translation to English by Benjamin Stevens.
The easiest way to edit the game is to use my editor InsmEdit. It is currently only available for Windows, but the included documentation has a description of the file format and how it patches the ROM, for those who would like to write their own patcher.
I started reverse engineering the game in May 2012 and soon released the first version of InsmEdit. In November 2012, I started making a commented disassembly.
To produce a commented disassembly (assuming you have the ROM image), download the disassembly comments and function map and use the disassembler like this:
MNVCDIS insmouse.vb insmouse.lst 8000 +13248 C comments.txt FM funcmap.txt FS
To extract the comments back from the produced disassembly, use the comment extractor.
The products of reverse engineering and creativity.
Some role-playing games (for example Dungeon Master) also use a similar visual style (which is why some non-Japanese magazines incorrectly classified Insmouse as one), but are not similar to Insmouse in gameplay.
Other Virtual Boy fan sites also have an Insmouse page, but no unique information.