You're looking for information on a classic game file!
file to prove you own the game. Once you point the A.I.R. installer to that Steam file, the magic happens. Pro-Tip: Codes to remember sonicknuckleswsonic3bin game file
The "Complete" Experience
The original lock-on technology had a quirk: The combined game allowed you to play as Knuckles in Sonic 3’s levels (Marble Garden, Hydrocity, etc.) but removed some of the original cutscenes. The early combined .bin ROMs sometimes restore those cutscenes. You're looking for information on a classic game file