If you have any interest whatsoever in goldeneye I recommend watching some videos from the youtube series "speedlore". It's a guy who has been speedrunning GoldenEye for 20 years (together with their community).
Due to the nature of speedrunning, there is a looooot of details about the game they've investigated and he goes through loads of examples throughout his videos. They definitely reverse engineer the games to figure out how they work so they can do more tricks etc.
The videos are looong but well worth the watch.
