How to create and install Endless Summer mods for Android: a complete guide

"Endless Summer" is one of the most atmospheric visual novels on Android, but even it is not without its drawbacks. Do you want to add new routes, change character designs or remove restrictions? Mods they allow you to transform the game to suit your preferences, but their creation and installation require care. This article will help you understand the process from scratch: from choosing tools to testing the result.

Many users are afraid to break the game for fear of crashes or account bans. In fact, with the right approach, the risks are minimal - the main thing is to understand what files can be editedwhich ones should not be touched. We will consider three types of mods: changing the text (translations, new dialogues), replacing graphics (sprites, backgrounds) and modifying the gameplay (opening hidden scenes, changing parameters). We will pay special attention security how not to lose progress and not violate the license agreement.

If you have never worked with files .apk or Unity-projects, don’t worry: the manual has a section for beginners with explanations of all terms. Experienced modders will find here up-to-date tools for decompiling and reassembling APK without losing the signatureas well as ways to bypass modification protection in the latest versions of the game.

1. Preparation: what you need to create mods

Before you start modifying, make sure you have everything you need. Basic tools are divided into three categories: for extracting game files, editing them, and reassembling them. Without them, you won’t even be able to open an archive with resources.

List of required software:

• 📂 APK Extractor (for example, APK Editor Pro or JADX) - for extracting files from an installed APK.
• 🎨 Image editors: GIMP (free) or Photoshop (for replacing sprites and backgrounds).
• 📝 Text editors: Notepad++ or VS Code (for editing scripts and configs).
• 🔧 Unity Modding Tools: AssetStudio or UABE (for working with game assets).
• 🔒 SignAPK —a utility for signing a modified APK (otherwise Android will not install it).

You will also need backup of the original game (save the APK and folder Android/obb to the cloud or PC). If something goes wrong, you can roll back. Do not edit files directly on the phone —use a PC for precise work.

⚠️ Attention: Modifying the APK may violate the terms of use of the game. Do not distribute mods publicly without the permission of the developers - this can lead to account blocking or legal consequences.

If you plan to change graphics, consider the resolution of the original textures. For example, character sprites in Endless Summer are often sized 1024×1024 pixels. If you replace them with images with a different resolution, the game may throw an error or stretch the picture.

2. Extracting and analyzing game files

The first step is to access the internal files Endless Summer. To do this, you need decompile the APK to study its structure. The easiest way is to use APK Editor Pro:

1. Download the APK of the game from your phone (for example, through Settings → Applications → Endless Summer → Export APK).
2. Open the APK in APK Editor Pro and select “Full decompilation.”
3. After unpacking, pay attention to the folders:
   • assets —scripts, fonts and some graphics are stored here.
   • res —interface resources (icons, buttons).
   • lib — libraries responsible for the operation of the engine Unity.

For deep modification (for example, changing plot branches) you will need to work with files .bytes or .asset in the folder assets/bin/Data. via AssetStudio:

1. Launch AssetStudio.
2. Drag the folder with the decompiled APK into the app window.
3. Select the desired file (for example, scriptableObjects.assets).
4. Export textures or scripts for editing.

Important: Not all files can be changed directly. For example, compiled scripts on C# (extension .dll) require decompilation via dnSpy, which is more difficult and riskier. Start with replacing textures or text - it’s safer.

3. Editing text and dialogues

The simplest type of mods is text replacement. In The Endless Summer, dialogue is often stored in files .json or .txt inside folders assets/StreamingAssets. They can be opened in any text editor.

Example of file structure with dialogues:

{
"scene1": {
"character": "Asya",
"text": "Hello! How are you doing?",
"options": [
{"reply": "Good!", "next": "scene2"},
{"reply": "Bad...", "next": "scene3"}
]
}
}

To change the replica:

1. Find the desired scene by name (scene1, scene2 etc.).
2. Edit the text in the field "text".
3. Save the file in format UTF-8 without BOM (important for correct display of the Cyrillic alphabet!).

For adding new dialogs you will have to:

• 📌 Create a new scene with a unique name (for example, scene100).
• 🔗 Register transitions from existing scenes ("next": "scene100").
• 🎭 Make sure that the game has graphic resources for the new character/background.

⚠️ Attention: If you add too much text, the game may crash due to buffer overflow. Test the mod on short replicas, gradually increasing the volume.

How to check if does the game support Cyrillic?

In the original version of “Endless Summer” the Cyrillic alphabet is displayed correctly, but in some mod builds there may be problems with the encoding. If, after replacing the text, hieroglyphs appear instead of letters, save the file in the encoding UTF-8 and check whether quotes or commas have been removed from the JSON structure.

4. Replacing graphics: sprites and backgrounds

Graphic mods take more time, but visually transform the game. In Endless Summer, character sprites and backgrounds are stored in .png or .texture2d (for Unity). To replace them:

Step 1. Export original textures

• Open the decompiled APK in AssetStudio.
• Find the desired sprite (for example, asa_neutral.png for Asya's neutral pose).
• Export it to PNG with maximum quality.

Step 2. Editing or replacing

• Open the exported file to Photoshop or GIMP.
• Keep transparency (alpha channel) and original resolution.
• If you add a new sprite, use the same size and color format (RGBA32).

Step 3. Import back to APK

• Replace the original texture with the edited one. AssetStudio replace the original texture with the edited one.
• Build the APK again using APK Editor Pro.

Example: to replace the background in the beach scene, find the file beach_bg.texture2d, edit it and import back. Do not change file names — the game searches for resources along exact paths.

Graphics type	File format	Editing tool	Risks
Character sprites	.png or .texture2d	Photoshop, GIMP	Distortion of animations when resizing
Backgrounds	.jpg, .texture2d	Photoshop	Compression artifacts
Interface icons	.png (with transparency)	Paint.NET	Offset of menu elements

☑️ Preparing graphics for mods

Keep original resolutionTest alpha channel (transparency)Use PNG format for spritesTest on different devices

Completed: 0 / 4

5. Gameplay modification: new routes and parameters

Changing plot branches or game mechanics is the most difficult type of modding. In "Endless Summer" the game logic is hardwired in scripts C# (files .dll in the folder assets/bin/Data/Managed). To edit them you will need:

Tools:

• dnSpy - decompiler and editor .dll-files.
• ILSpy - alternative for viewing code.
• UnityExplorer - for debugging directly in the game (requires root or an emulator).

Example: how to open a hidden scene

1. Open Assembly-CSharp.dll in dnSpy.
2. Find the class responsible for game progress (for example, GameProgressManager).
3. Change the scene unlock condition (for example, replace if (unlocked == true) to if (true)).
4. Save changes and rebuild .dll.

Warning: Not all changes will work. For example, if you try to add a new character without his sprites and voice files, the game will throw an error NullReferenceException. Always check modifications on emulator (for example, BlueStacksbefore installing on your phone.

Critical detail: when When editing DLL files, the game may stop launching due to checksums. In this case, you will need to patch global-metadata.dat or use tools like Il2CppDumper to bypass the protection.

6. Assembling and installing the mod on Android

After editing the files, you need to assemble the APK back install it on your phone. Here are step-by-step guide:

Step 1. Sign the APK

• Use SignAPK or the built-in function in APK Editor Pro.
• If you do not sign the APK, Android will issue error INSTALL_PARSE_FAILED_NO_CERTIFICATES.

Step 2. Installation

• Delete the original version of the game (or make a backup of the data via Titanium Backup).
• Enable installation from unknown sources: Settings → Security → Unknown sources.
• Install the modified APK and copy the folder obb (if it exists) to Android/obb/[game package].

Step 3. Testing

• Launch the game and go through the test section (for example, the first scene).
• If the game crashes, check the logs via Logcat (in Android Studio).

⚠️ Attention: Some mods may conflict with cloud saves. If you use Google Play Games, disable synchronization in the game settings before installing the mod.

If the mod does not work, return to the original APK and check:

• Whether critical files were deleted during editing.
• Whether the checksums of the modified resources match.
• Whether the folder structure has changed (for example, the case of characters in file names is important for Linux systems!).

7. Common errors and their solutions

Even experienced modders encounter problems. Here are TOP-5 errors when modifying “Endless Summer” and ways to fix them:

Error	Cause	Solution
The game does not start	Incorrect APK signature	Re-sign the APK using SignAPK keys from platform.x509.pem.
Black screen when loading	Damaged textures	Check the graphics formats (should be RGBA32 for sprites).
Crash when selected dialog	Error in the JSON structure	Validate files through JSONLint.
No sound	Deleted/damaged .oggfiles	Restore the original audio files from the backup.
Animations are jerky	Changed sprite size	Return the original resolution or edit the animation files (.anim).

If you see error Unity Player [version: Unity xxxx], which means the problem is in the modified .dllfiles. Try:

1. Return the original scripts.
2. Use Il2CppDumper for correct patching.
3. Check changes on the emulator, not on the real device.

For debugging, use ADB Logcat. Connect the phone to the PC and run the command:

adb logcat | find "Unity"

This will show errors related to the game engine.

8. optimization and distribution of mods

If your mod is ready and working, you can share it with other players. But before that, consider a few nuances:

Optimization:

• 📦 Reduce the APK size by removing unnecessary resources (for example, unused language packs).
• 🔄 Check the mod on different versions of Android (from 7.0 to 14).
• 🛠 Use ProGuard to obfuscate the code (protection from decompilation).

Distribution:

• 🌐 Upload mods to specialized forums (for example, 4PDA or ModDB).
• 📋 Add a detailed description of the changes and installation instructions.
• ⚖ Please indicate that the mod is intended for personal use only (to avoid copyright issues).

If you plan update the mod for new versions of the game:

1. Compare the original APK files with the previous version (for example, through WinMerge).
2. Transfer changes manually - automatic merging can break the logic.
3. Test on a clean installation (without old saves).

⚠️ Attention: Some anti-cheats (for example, in multiplayer modes) can block modified APKs. If in “Endless” summer" there will be an online competition, your mod may be blocked.

FAQ: Frequently asked questions about mods for "Endless Summer"

Is it possible to make a mod without a PC, only on a PC? phone?

Technically yes, but it is extremely inconvenient. Editing textures and scripts requires powerful tools (Photoshop, dnSpy), which are not adapted for mobile devices. The maximum that can be done on the phone is to replace textures via MT Manager, but the risk of errors is high.

Will there be a mod? work on an emulator?

Yes, but there may be problems with graphics (for example, BlueStacks sometimes transparent PNGs are not displayed). For testing, it is better to use an emulator with support for OpenGL ES 3.0+, for example, LDPlayer or MuMu Player.

How transfer the mod to another version of the game?

Compare the files of the new and old version via WinMerge. Migrate changes manually because automatic merging may break resource dependencies. Pay attention to the files global-metadata.dat —their structure may change.

Is it possible to modify saves (for example, increase sympathy points)?

Yes, but to do this you need to edit the save files in the folder Android/data/[game package]/files. They are usually in the format .sav or .dat. Use a hex editor (for example HxD) or specialized tools like Save Editor.

Is it legal to distribute mods for Endless Summer?

From a legal point of view, modifying a game for personal use is usually not persecuted. However distribution mods may violate the license agreement, especially if they modify paid content (for example, open DLC). Always check the rules on the official website of the game.