fg-optional-bonus-soundtrack.bin is a component of a FitGirl Repack, typically associated with the game
Modern AAA games are massive, often exceeding 100GB. Repackers like FitGirl use heavy compression to shrink these files down to 30% or 40% of their original size. To make the downloads even smaller, they often strip out "extra" content into separate files. Common optional bins include: : Digital music. fg-optional-credits.bin : The end-game credit videos. fgoptionalbonussoundtracksbin