BBS was one of the more concise games in this series, and even answers questions that people used to have about 2. Like...
>How did Riku know he was the chosen one?
>How could Kairi possibly have a Keyblade?
>Why does Sora's Nobody look like a completely different guy?
>Who were the "Keyblade Heroes" that Xigbar just casually mentioned in the final level?