I recently acquired the FFVIII PC edition, which comes complete with Chocobo World! I just started this little game (Boco is only level 4), but I have already acquired an "A" item, which every walkthrough indicates is the rarest item in the game, and nearly impossible to get, due to the item generation methods. Haven't transferred it over yet, because I haven't yet reached Boco (I'm only at the first dream sequence), but I am very much looking forward to claiming this uber-rare item.
Has anyone else obtained any rare/special items in Chocobo World?