Earlier this week, it was announced on social media that a lost Resident Evil game for Japanese phones had been partially preserved, thanks to the efforts of those within the Japanese feature phone preservation community.
Biohazard: The Operations was a title released in 2007 and rather used assets from the Resident Evil GameCube remake, as noted by feature phone preservation expert RockmanCosmo online.
The game appears to follow a similar gameplay-style to the Resident Evil 3-themed mobile titles, Biohazard: The Missions, Biohazard: The Missions, Biohazard: The Episodes, and reportedly featured around 100 missions as well as a scenario mode where players could play as either Chris or Jill.
Doing some digging online for old Japanese articles from the time of release, we weren't able to find much information about the game except for an initial announcement from the time of release. This covered the game's release for EZWeb-compatible phones, but it appears the game also got an i-Mode version at some point as well, which is the version that has now been partially recovered by the recent preservation effort.
Yuvi, a fan translator, preservationist, and hacker (who we've interviewed on the site before for his ongoing work in trying to bring back Before Crisis: Final Fantasy VII), was the person who led this amazing recovery, announcing on Twitter/X that he had recently dumped the game from an F904i handset, and had gone through the effort of getting it to function once again.
In a long thread, he went into detail about the numerous difficulties he faced in getting the game to run, stating that he not only "had to create a server and recreate the whole Spencer Mansion one scene at a time", but also had to compensate for missing SD Card data, which caused frequent crashes.
Yuvi wrote:
"After digging into the code and testing, I discovered the app required “scene files,” which were primarily background images accompanied by text files. The next challenge was that I had no idea what image IDs, or references the game expected, and much of the code was heavily obfuscated. To work around this, I generated plain black images labeled with ID numbers so I could track exactly which files the game was attempting to load
"From there, the most difficult and time-consuming step began: painstakingly reconstructing the mansion, one scene at a time. Essentially, I would enter the game, move around in a pitch-black void, and try to deduce which part of the map I had reached. Thankfully, the game does include a working map that displays your current section of the mansion—though it doesn’t indicate which frame—so it served as a reference. Over the course of about 30 hours, I rebuilt the entire mansion piece by piece from those black voids.
"Luckily, the app uses assets directly pulled from Resident Evil Remake (GameCube), which made the process much more manageable. And that brings us to this release. What was once destined for the “not working” pile due to missing data has been revived into a 95% functional game."
Yuvi describes the preservation effort in the description of a recent YouTube video as a "labour of love" and also speculated the footage he shared might actually be "the first real footage of this game online today". This is something we haven't been able to verify, but it seems incredibly likely, given that the only mentions of the game we found all seemed to make use of the same handful of screenshots.
If you're wondering what is now playable following Yuvi's recovery efforts, it appears that you can now experience all of Chris's scenario missions, as well as the 100 operation missions, and all of the extra missions. In addition to this, you can also access the online leaderboards, as well as all shop features and items — though, as Yuvi notes, Jill is sadly not yet available.
A partial English translation patch is also available thanks to Yuvi, @SnowyAria, and @Shentok_, with this translation covering "most system text, item names, and location names", to help you progess. If you want to play the game, it should be available via the Keitai World Launcher.