Revisit Kashyyyk, Felucia, and Raxus Prime under Imperial control.
The main campaign follows Starkiller through several iconic locations, often requiring you to revisit planets as the story progresses:
While the specific .zip file you mentioned is likely a community-packaged file containing various resources, a for STAR WARS: The Force Unleashed (2008) typically covers the mission walkthroughs, collectible locations (Holocrons), and combat strategies for Starkiller's journey. Core Walkthrough & Missions