DISCLAIMER: The downloaded files are to be used at your own responsibility
The lost Unity Standard Assets, in a .unitypackage importable file. They can be downloaded in three different ways:
a) Clone the repository and combine the 4 StandardAssets.unitypackage.00x files.
b) Download the assembled .unitypackage file from the GitHub Releases.
c) Direct download link to the assembled file: https://github.com/marticliment/UnityStandardAssets/releases/download/0.0.0/StandardAssets.unitypackage
Once downloaded, they can be added to Unity following the usual importing process, via Assets > Import Package > Custom package....
Tested to work in:
- Unity 2018 (latest release)
Not guaranteed to work on Unity 2019 and higher. However, some tweaks exist that can help them work: https://www.youtube.com/watch?v=XSOhkbO8xEA
I installed the Standard Assets package from my Unity Assets library and I have repackaged them into an importable .unitypackage file, so they can be imported via Assets > Import Package > Custom package....