Coming from an IGN interview with Eiji Aonuma, Shigeru Miyamoto and Bill Trinen...
Aonuma on the challenge of creating a big game world
“After Skyward Sword we really needed to develop a bigger world, but we've actually never done that. A lot of it was trial and error, and we had to feel things out. We talked a little bit about the idea of density, how dense do we make this big world. As we were developing it, we realized that filling [Hyrule] with things to do and explore is going to be a lot of work. It's going to take a lot of people and a lot of time. But when we actually started doing it and experienced things like moving around on the horse or climbing up to a high place and paragliding down, we realized that our desire to see what's ahead was more than just wanting to see what's in the world. So in that sense, we realized that it's kind of OK if there are pockets of emptiness.
During development I noticed this idea of actually getting lost is fun. Getting lost in those small worlds, it's not a loss of what to do but it's more of a directional loss. I see the exit but I can't figure out how to get there. That can lead to frustration, but when everything in the world is connected, [you end up] challenging something in a way that ‘I think this is going to work’ and then discover that ‘Oh, this isn't going to work.' It's not actually a painful experience. It's actually fun. It's a sense of discovery and, as we're developing this, I thought to myself, ‘Maybe this is what it means to create a big world.’I learned that getting lost is OK.”
Aonuma on Elixirs
“So there's definitely different types of medicine. For example, as you saw there's elixirs to make you walk faster, and there's an elixir that will nullify any sound you make. There's all these different effects, there's many different effects that will help you accomplish your goal. There's many great different types of that. If you're going to a cold area, if you drink the right type of elixir you can go there half-naked and you'll be fine.”
Aonuma on Rupees, Towns, and the Upgrade System
“Rupees do exist, but the reason for their existence is a little different this time around. As you saw it's not about going to cutting down grass and collect rupees or find them in treasure chests but it's about collecting things and going to sell them and then using the rupees you get to buy new things. The rupees are there but they serve a different purpose.
I can't share too much about villages because the way they work is interconnected to the story and overall world. It would be spoilers, so I wouldn't want to do that now. I think that in adventure games the idea of meeting people and saying farewell to them is an important aspect. So that's definitely in there.
Termina is one of the most important aspects of Majora's Mask. But to say that we took that thing and just plopped it into Breath of the Wild would be incorrect. Of course, I mean, it took about a year to make that town [for Majora's Mask]
...so the upgrade path is very Zelda-like.
When Mr. Aonuma was asked if the upgrading takes place within towns, he answered with, "Not quite" followed by a laugh.
Aonuma on the special arrow from the original footage
“Yes, you're right that arrow is definitely an important part of the game and actually getting that arrow is very important to navigating the game. To reveal it now would be a spoiler so I don't want to say too much.”
Aonuma on the green tunic
"One convention we haven't challenged, as you probably saw in the second demo, is that again Link awakens from slumber. So, you know, the green tunic maybe, maybe not.
The clothes he's wearing right now is actually the same clothes that he was wearing in the trailer that we've shown previously. We thought that having him wear this tunic for this demo would make it a little more familiar to people watching the game demo and trailer this time around. Link gets that blue suit at a very important juncture in the storyline, and we also showed suit of armor you can get too. There's also times when Link will venture out into the cold and he'll need to appropriately equip himself, so there's definitely a lot of variation types of clothes he can wear.”
Miyamoto and Bill Trinen on the open world aspect
“Sandbox games is what they’re typically called here, but before anybody called them sandbox games, I always described Nintendo games as being a garden in a box. Zelda is a garden in a box game where the player can freely go around and experience [the world]. There are quests. Sometimes we call them little chores that we need to do, but there are missions. On the systems side, you get a list of missions that’s easy to look into and check on." - Miyamoto
"Those missions are, obviously, optional and even the way the story is set up, once you get off the plateau you’ll get to a point where you’re given some options of things you can pursue. You might want to pursue the story. You may want to try to learn more about Link’s background, or you might want to go and try to solve all of the Shrines. You get to this point where you’re able to choose which one of these directions you want to do first, and then you’ll get missions that are layered on top.” - Trinen
Miyamoto and Bill Trinen on story
“This game has a heavy focus on experience and also freedom. It’s not really story heavy. You can choose to do all of the tasks and all of the missions and you’ll still get to the end, or you could choose not to do all of them, and you can still get to the end.
The story isn’t as clear cut as it was in the past with the existence of Ganon, Link, and Zelda. With this one it’s a little bit more vague. You’ll kind of feel what Ganon is, and you’re going to feel maybe this is what Zelda is like, or this is what Link is like. It’s really Link’s adventure in discovering all of that." - Miyamoto
“They’ve done a really good job of weaving the story into the world, giving you just enough direction to know, generally, where you need to go to pursue it. If you’re off doing other things and you decide you want to go complete the Shrines, or you want to go climb mountains, or you want to go look at deer in the field, or find that pond that had all the ducks in the trailer, you can do that.
I get into the game and then go off to do random things. Then, maybe after a couple days of playing, I’ll think that maybe I should actually go to that place [someone I met in the story] talked about. Then, you go there and get enough clues to point you in [the next] direction. It’s does a really good job of guiding you to where the story is, but it still feels like a sort of chance encounter out in the world when you come across somebody who has a role to move the story forward.” - Trinen