Kingdom Hearts: Realm of Dawn

I don't know about you, but I think there should be a Kingdom Hearts storyline game that shows us Riku and Aqua's journey in the Realm of Darkness. Cause I'm curious to what Aqua's doing and how Riku got out.

I even figured out how the whole thing goes. THe only thing I couldn't figure out is a title. I was thinking maybe "Realm of Dawn" or "Into the Darkness":

The story starts at the very ending of Kingdom Hearts, after the door to darkness is closed. Riku and Mickey travels around the realm of darkness, trying to find a way to escape, but Riku goes off on his own, deeper into the darkness. Meanwhile, Aqua tries to find a way to escape so she could help her friends, but then she arrives at a strange world, only to soon realize it's the Castle of Dreams, cinderella's world, shallowed by the darkness. Aqua enters the castle to see if there's anyone that could help her. Riku finds the castle and enters, to see if there's a way out of his prison of darkness.

Aqua and Riku both get into a tough battle, but as they battle, they soon bump into each other. They team up to defeat the darkness. After the battle, they introduce each other, and soon realizes they've met before, ten years ago. For Aqua, realizing how grown up riku is puts Aqua into a shock, noticing how long she's been gone.

Aqua and Riku decides to team up to fight the darkness and find a way out of the realm. I figured the worlds they visit should be those that were shallowed by the darkness but never returned:

City of Bells - Hunchback of north dane
Prankstar's paradise - Pinocchio
Enchanted Dominion - Sleeping Beauty
Dwarf Woodlands - Snow White
Land of the Heavens - Tangled
Invaded island - Lilo and Stitch: Earth version
Radiant Garden - The BBS version
The Frozen Wastelands - Frozen
Cocoon - Final Fantasy XIII
Midgar - Final Fantasy VII
Ring of Chaos - Battlteground area like BBS Mirage Arena

And the final world would be the Realm of Darkness itself. Personally, I wonder what the final boss should be. I was thinking it could be either Xenahorts Shadow, Sora's heartless, Riku's darkside or Vantius - Ventus's Shadow.