As you go through the game you complete worlds. Each world is a floor of the Castle of Oblivion.
All you need to do is clear 5 floors to unlock this achievement.
The 1st world is Traverse Town (1F)
The next 4 you can pick from the following:
Agrabah (Aladdin)
Olympus Coliseum (Hercules)
Wonderland (Alice in Wonderland)
Monstro (Pinocchio)
Halloween Town (Nightmare Before Christmas)
Upon completing 5/6 worlds and exiting "Exit 5F" a cut scene will happen watch this cut scene and you should be on 6F entrance Hall......... this has not unlocked for me
So now im on 7F .........
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