Since you are looking for a "long piece" related to this specific version and edition, here is a deep dive into what this package represents, the state of the game at version 3.5.3, and the unique features of the Galaxy Edition. 1. The Package: What is Part 4?
A deep dive into the art and design philosophy behind the various alien races and ship designs. Stellaris.Galaxy.Edition.v3.5.3-GOG.part4.rar
If you are having trouble with this specific part, keep in mind: Since you are looking for a "long piece"
A digital copy of the Stellaris novel by Steven Savile, which expands the lore of the universe. A deep dive into the art and design
Because it is a GOG (Good Old Games) version, the installer is DRM-free. This means once installed, the game does not require a launcher or internet connection to verify ownership, which is why these specific GOG archives are popular in archival and sharing circles. 2. Version 3.5.3: The "Fornax" Era