Unlike the standard edition, the Galaxy Edition includes out-of-game collector's items and a minor in-game cosmetic:

A 71-page art and design book detailing the game's aesthetic development.

The v3.5.3 patch focuses on streamlining the mid-to-late game and improving the competitive nature of AI empires. So what is the difference between the editions?

A digital novel by Steven Savile set in the Stellaris universe.

Exclusive forum avatars, a galaxy forum icon, and a signed desktop wallpaper. Key Features of v3.5.3 (Fornax Update)

Over two hours of original music, including bonus tracks and orchestral versions.

Adds a unique arachnid species portrait for your empire.

The (specifically the v3.5.3 "Fornax" update) combines the core grand strategy experience with exclusive collector's content and significant gameplay refinements focused on AI and balance. Galaxy Edition Exclusive Content