The concept art from Retro Studios recently found their way online and illustrated the cancellation of spin-off games based on The Legend of Zelda and Mario Franchise. IGN found ex-Retro Studios artist Sammmy Hall who produced the images and explained that both the titles Shiek and Boo from Mario are in the pre-production phase and canceled.
"I doubt many of Nintendo's deserving ones see much of that stuff. I've been particularly drawn to a room like Milton from Office Space and assigned to think work among other tasks."
Sammy Hall
“Zelda's hiding from the Ocarina of time. It was to be an action-JRPG, set behind the dark Ocarina of Time timeline, when the last man Sheikah walked across the desolate Hyrule while the Green Gerudo tribe gave birth to a new kind of Ganon. Obviously it would have been the story of the origins of the Great Sword. ”
"One is a role-based game like Booo in the Mario series, which probably has the name Haunt, and it looks like it was designed for hand-to-hand consoles.
IGN
The original idea for the games came from the likes of Ret-Retro, Mark Pacini, Todd Keller and Kynan Pearson and the cancellation took place as they moved into the new studio. However, it is possible that Retro terminated the project or was asked to explore other new ideas in the established series, such as Donkey Kong.