This comes from Nintendo's GDC panel and is 100% legit. I know it's crazy to think about, but this really does exist!
Very cool. I can see as well how they've drawn so many comparisons to the original Zelda especially with this prototype in mind. It's also really cool to see how they made these concepts in a 2D world and brought them to life in a 3D world.
I wonder how much some games design would change if they first made prototypes for some mechanics in 2D before they made it in 3D. I feel like some ideas are easier to get across in a 2D world, whereas bringing them to life in a 3D world would require a bit more creativity and design to get them across effectively.
Coolest thing I've seen in awhile.
So, eshop title this, Nintendo.