-change the art style
Specifically, to something more mature. It doesn't have to be 'dark' like TP. But the visually intriguing, 'enchanted' feel of the Zelda Wii U Tech Demo had me so enthralled, I was honestly dismayed when I saw the first trailers for BoTW. Zelda seems to be getting too attached to a cel-shaded, cutesy feel (especially in light of the LA remake) and this is worrying to me.
https://www.youtube.com/watch?v=fxvM1A_uHuI
-out with the old
The kingdom of Hyrule, the Master Sword, especially, it's very overdone at this point. Have Link explore a completely new kingdom, with its own, storied history. Perhaps even get rid of Princess Zelda and the Triforce.
-balance out the overworld/underworld
In the original LoZ, the dungeons were known as the 'underworld', because they mirrored the overworld. I don't know for sure, but I think the collective dungeons were bigger than the overworld itself, by number of screens.
For the next Zelda, I want the developers to sort of go back to this philosophy. Cut down on the size of the overworld to about 50% and then create an 'underworld' that is roughly the same size. What's the point, you ask? Well, in the game I envision, you are encouraged to tunnel into the underworld in the process of exploration. There would be lots of moments where, owing to the topography and sheer height of mountains that you will probably have to go under to get past. So the underworld would function like an 'underground'; there would still be dungeons, but they wouldn't function like traditional dungeons. They would be so large, you wouldn't be expected to explore each one fully the moment you arrive necessarily, and dungeons would link up to neighbouring ones. There would even be entire settlements underground. Because you would have to weave in and out between the overworld and underworld during normal course of play, the two worlds would feel more composite, and it would feel like one very maze-like world. (It would be very important though that there would be no loading screens)
-design the overworld with more flair
To me this a real no-brainer, but really try to do something other than forests, snow regions, volcanoes... This is a
fantasy game, the possibilities are literally endless, and for Nintendo to fall back on the same tired environments for 30 years now is just disappointing.
Please do something more abstract and creative.
-more emphasis on cities
And make these cities sprawling and fun to explore in their own right.
-cut down on the items, please!
One sword, one shield, one bow is enough. Maybe focus more on an upgrading system?
-hire a better composer
-write a better story, get rid of the MacGuffins, and make me feel for the characters
I don't care if you make the game more linear as a result.