How do I extract assets from a pre-compiled Unity game?

You can with Unity Assets Explorer: http://forum.xentax.com/viewtopic.php?f=10&t=10085

You can't. Unity specifically builds its games in such a way as to make it extremely difficult to do this.

Why do you need to extract assets from this game? If it's something you have legitimate access to, can't you just ask the original creator? If it's a game you created, but have subsequently lost the project file for, then bad luck. You should have kept better backups.

Utility DevXUnity Unpacker Studio

http://devxdevelopment.com/UnityUnpacker

Video - Generate Unity Project from Game distributive (win, apk -> Unity3d project)

Functionality:

• Opening of distribution files (Unity standelone files (win, MAC, linux), apk, ios)

• View scene structures

• View resources content (text, images, sounds, meshs, scripts, scene objects)

• View scripts source code (decompile)

• Export resources and scripts (convert image asset to PNG, DDS, sound to WAV, export Mesh to .obj format, decompile assemblys and etc.)

• Export with make unity project (scenes, plugins, scripts, resources) (only for DevXUnity-UnpackerStudio type license)

• Replace content in assets: (for standelone games)

  • replace textures

  • replace text

  • replace sounds

  • change asset header fields

• Replace and view all strings in assembly

Support Unity3D Asset types:

• Texture2D (support convert to PNG)

• TextAsset

• Mesh (support convert to Obj format)

• AudioClip

• MeshFilter

• Material

• Renderer

• GameObject

• Transform

• GameObject and other..

Formats resource file names: level ; mainData; CustomAssetBundle- ; CAB- ; BuildPlayer- ; .assets; * .sharedAssets, and other..

Opening APK files with the ability to view and export the contents of the package. - .apk

Opening Unity bundle files with the ability to view and export the contents of the package:

• .unity3d;

• .unity3d.lz4;

• .assetbundle;

• .bundle;

• .bytes

Think twice before you consider purchasing DevXUnity Unpacker Studio.

I had recently really bad experience with it. In my case it even didn't work, it crashed around 60%. Customer support and general communication is non existent. Developer had quite quick response for presale questions (Usually same day), but after purchase I didn't receive any response for weeks when the program just crashed. After I opened the claim at Paypal he again responded and got the screenshots and debug logs but finally I think he just gave up as he was unable to fix the program.

But the most important thing, I did check what did it manage to export within that 60% and I have to say there was nothing more special than uTinyripper can do. With uTinyripper you have to decompile the scripts yourself and the program did apply some C# patches that you will have to do yourself (Anyone trying to reverse engineer Unity will have to know C# anyway) but other than that there was no better result than open source tools can provide. Addition to that you have to be aware that the program requires constant Internet connection and you have to make an exception to your antivirus software to allow it to run. I would not suggest to run this application on your main workstation as in reality you can never be sure that it does not contain malware that could harm your computer or log your keystrokes etc. Also you have to take into consideration that when developers server is down you are not able to use that software. So for example when the developer realises that his software does not support additional value to those open source softwares and stops hosting his license server you will also lose the access to the application.

I had great success using Unity Assets Bundle Extractor.

Here is a quick tutorial on how to use it.