*cackling* Wouldn't it be hilarious to see Sora, Donald, and Goofy shrunk down to mouse-size fighting Lucifer alongside Jaques and Gus?
Oh, to see Cinderella's challet from the size of a mouse... going through all the secret passages for the critters, flying on the birds... o_o climbing those stairs. *grins* though Sora could use the keyblade to hoist himself up the stairs. After all, in the movie Jaques and Gus had to get the key to Cinderella's room upstairs before the Duke left with the glass slipper.
Chasing the "flying on the birds" idea... what if they did Cinderella's world as a mini-game world, like Winnie the Pooh? I mean... what if you had to deliver a message to one of the other mice, but you can't get across the yard on foot because Lucifer is guarding the door, so you had to ride on one of the birds and dodge obstacles? There could be a food-gathering game, too... you could choose to either help gather the food or fend off Lucifer from the other mice.
Maybe you'd have to do all these games to become normal-sized again... and once you were normal, you'd have to keep her from meeting the wrong prince at the ball, like a Heartless or Nobody posing as the prince.
Don't quote me or take me seriously, I'm just rambling.
*mutters* So what if I watched Cinderella recently...