Here is a deep dive into what this file is, why it exists, and whether you actually need it on your hard drive. What is fg-optional-soundtrack.bin?
The "fg" in the filename stands for , the pseudonym of one of the internet’s most famous "repackers." Repacks are versions of video games that have been heavily compressed to make downloading easier for those with slow internet or data caps.
You may have chosen not to download it, which is fine—the installer will simply skip it and the game will still work. The Bottom Line
These are mandatory. Without them, the game won't run.