Hey everyone!

A little while ago I started digging into Digimon Heroes to see how much of the game could still be preserved after its shutdown.

I previously made a post asking the community for surviving files and old installations:

Previous post:
https://www.reddit.com/r/digimon/s/CBttrNDILt

Since then, the project has made some real progress.

The video attached to this post shows the current state of the reconstruction. It is still very early, incomplete, and there is a lot we do not understand yet, but we can now reach and interact with parts of a battle again.

This has involved researching surviving game files, APKs, recovered data, decompiled code and the original client's behavior.

The goal here is preservation and research.

I'm not trying to launch a public/private replacement server or commercially redistribute the original game. I mainly want to document how Digimon Heroes worked and recover as much of its original behavior and data as possible before the remaining pieces disappear completely.

TL;DR

If you still have an old Android phone, tablet, emulator or backup where Digimon Heroes was actually played, please don't uninstall the game, clear its data/cache, or open it yet.

The two most valuable files we're currently looking for are:

btlsav.mim

especially one created while a quest/battle was active,

and:

data_resources_new_EN.dat

from a real old installation.

Full backups of the game's private data, old network captures and screenshots/videos of gameplay can also help.

At the moment I do NOT need more APKs. I already have many different APK versions.

I also do not currently need extracted image assets, artwork or music/audio files. A significant amount of that material has already been recovered.

What we need now is mostly runtime data, saves, caches, configuration and information generated while the game was actually being played.

You don't need to know how to extract anything. If you find an old device or backup, just contact me first and we can figure out the safest way to preserve it.

What we need the most right now

1. Old Digimon Heroes installations

The most valuable thing that could still exist is an old Android phone/tablet where Digimon Heroes was installed and played.

Even though the servers are gone, the phone itself may still contain information that cannot be recovered anywhere else.

If you still have the game installed:

Please do not:

• uninstall it
• clear its app data
• clear its cache
• reinstall it
• update/replace the APK
• open the game yet

Ideally, leave the device exactly as it is until we can make a copy of its data.

2. btlsav.mim

This is currently one of the most important missing pieces.

We are especially interested in an original:

files/btlsav.mim

Ideally, one that was created while the player was inside a quest or battle.

From the reconstruction work so far, this file may contain or help us understand information related to:

• battle state
• player/enemy HP
• turns
• enemies
• selected cards
• actions
• battle progression
• battle results

An authentic battle save could answer several questions that we currently cannot safely reconstruct from assumptions alone.

3. data_resources_new_EN.dat

The other extremely important file is:

files/data_resources_new_EN.dat

from an actual installation of Digimon Heroes.

We're also interested in associated resource indexes, manifests and caches that may exist alongside it.

Right now some parts of the research environment have to use reconstructed/synthetic information because we don't have a confirmed authentic copy of all of this data.

An original file could potentially resolve a lot of uncertainty.

4. Complete backups of the game's private data

If you ever backed up your old Android phone, emulator or applications, that could be extremely useful.

The original app package was:

com.bandainamcogames.google.digimonheroes

We're especially interested in surviving contents corresponding to things such as:

• files
• cache
• shared_prefs
• databases

or, ideally, a complete backup of the application's data directory.

Even if you don't recognize any of those names, don't worry.

If you have an old phone or backup that contained Digimon Heroes, just let me know what you have.

5. Old network captures or logs

This is a much bigger long shot, but potentially extremely valuable.

If you were into Android modding/development/network debugging back then and happened to preserve anything from Digimon Heroes, we're interested in things such as:

• Charles Proxy sessions
• Fiddler captures
• HTTP proxy captures
• packet captures
• Android logcat
• old DNS/hosts configurations
• saved HTTP requests or responses

In particular, historical responses related to things such as:

api50/get_image_list

login

quest/battle initialization

could contain information that disappeared when the original servers went offline.

Server responses are one of the hardest things to reconstruct because, unlike client assets, we cannot simply extract them again from an APK.

6. Screenshots and videos are still useful

Screenshots and screen recordings are still welcome, particularly if they show actual gameplay behavior or content that is poorly documented.

Things such as:

• battles
• quests
• events
• menus
• card behavior
• decks
• enemies
• rewards
• loading sequences
• login flow
• late-game content
• error messages
• screens from near the end of the game's lifetime

can help verify how reconstructed systems are supposed to behave.

What I DON'T need right now

Just to save everyone some time:

APKs

I currently don't need additional APK files.

I've already collected many versions of Digimon Heroes, so another ordinary APK is unlikely to answer the questions blocking the project right now.

If you have something unusual — such as a clearly undocumented version or an APK bundled together with its original app data — that's different.

But otherwise, APK preservation is currently well covered.

Extracted images and music

I also don't currently need general dumps of the game's images, artwork, sprites, backgrounds or music/audio.

A large amount of that content has already survived and been recovered.

The major gaps right now are related to data created or downloaded while someone was actually playing the game, rather than static assets bundled with the client.

You don't need technical knowledge to help

This is probably the most important part of the post.

If you find an old phone, tablet, emulator, PC backup, SD card or Android backup that might contain Digimon Heroes:

you do not need to extract anything yourself.

You don't need to know ADB.

You don't need to root the phone.

You don't need to understand Android's directory structure.

Just tell me what device you found and what condition it is in.

From there, we can figure out the safest way to inspect and copy the data without accidentally overwriting something important.

The priority is always to preserve the original first.

Why I'm doing this

Digimon mobile games have an unfortunate history of disappearing after their services shut down.

When that happens, it isn't just the APK that is lost.

Server behavior, events, battle logic, progression systems and sometimes huge portions of the actual game can disappear with them.

Digimon Heroes is already in that situation.

But the progress shown in the attached video makes me much more optimistic that we can still document and reconstruct a meaningful amount of it.

The catch is that some of the missing pieces may exist only on old devices that haven't been touched in years.

So if you played Digimon Heroes:

please check that old phone in your drawer.

Even if the game hasn't worked for years, what is still stored on that device might contain something nobody else has anymore.