The following interview details come from a Famitsu interview with Skyward Sword producer Eiji Aonuma and director Hidemaro Fujibayashi...

Aonuma: "It's funny, but Fi, the sword-spirit who appears in this game, was something we finished up before we decided this would be a Zelda that used Wii MotionPlus. We already had her as a sword spirit beforehand, and during our announcement at the 2009 E3 show, her design was modeled after the Master Sword. At the time, though, you used her in a completely different way gamewise than you do now. The MotionPlus swordplay was something that was completed later on, and as a result the game's story and action gameplay came to both focus more on the Master Sword. It wound up coming together pretty well."

Fujibayashi: "From our previous experience, we knew that Zelda needed some kind of character that was there to explain the situation to you. Link, the hero, doesn't speak, so you need someone else talking to you if you want to give hints to the player. That sort of character also serves to expand on the game's world -- you have someone who handles navigation for the player and also holds a lot of responsibility for telling the story. Fi is the character who serves all those purposes in this game.

Something that always gives me trouble when I'm working on Zelda is the fact that, although the point of his adventure is always to save Princess Zelda, that seems more and more contrived the further away Zelda is from Link in terms of relationship. It's like you see this girl for just a moment and you're supposed to want to rescue her because she's probably a princess or something. One of the themes here was to figure out how to really make the player think 'I want to save her!' instead of just making him do so as part of the story progression. The game's story would start to drag if we spent a long time framing this at the start, though, so having them be childhood friends is what we thought was the quickest and easiest way to establish their relationship and portray them in this new world.

In previous games, once you were separated from Zelda, you really didn't see her again until the very end of the game. That makes it harder to keep the player motivated through the whole adventure. We've tried to make it easier to care for Zelda in this game, but that won't be enough to keep the player going to the end, so you also have several near-misses with Zelda throughout the game. We tried to have it so you miss Zelda only by the slimmest of margins -- you have enemies like Ghirahim saying things like 'Zelda's right on the other side of this door.'

There are two reasons for this (Link returning to Skyloft). First, Aonuma requested that the system you use to choose the field you're adventuring in be simple, streamlined, and compact. Second, I liked skydiving so I wanted to do something like that."

Aonuma: "Having the sky be your base allows for easy access to all of the worlds. We hadn't thought about loftbird-based transport at the start -- instead, it was more a case of if you fall off Skyloft here you'll go to the forest, or if you fall off there you'll wind up by the volcano. We realized, though, that that wasn't very realistic -- being able to access all these vast, different worlds from a single small island in the sky -- so that's where the loftbirds came from."

Fujibayashi: "This wasn't how it was organized during the concept phase (returning to three main locations). During development, when we looked at the balance between the size of the world and what we wanted to do, the world was too big and a little too thinly spread out. We decided instead to limit the game to three regions and make each one a lot more dense. I can't talk about exactly what sections we were thinking about [that got cut], but much of it wound up getting used in the game regardless in the end.

This game has the Wii MotionPlus sword action, but the most fundamental part of Link's skill set is his search-and-discover skills, the A-button dashing and climbing and so forth. We wanted it to be fun to find hidden areas and such using Link's own physical skills instead of relying on items, and we were also thinking about how to add a sort of hide-and-seek aspect to the game."

Aonuma: "Phantom Hourglass and Spirit Tracks both had the Phantoms, which you couldn't fight so you had to run from. We thought it'd be fun, once you were used to fighting with your sword, to have a situation where you're thrown into a new world defenseless and have to figure out what to do from there. We wanted it so you needed a real strategy in order to survive. We were thinking about doing Siren in the form of a dungeon at first, but this type of gameplay works best when you're already intimately familiar with the field it's taking place in, so we revised that approach pretty quickly. As a result, the Siren world came together at a pretty early point in development.

It's not really the sort of thing where we can say 'This is how we do it,' (concerning dungeons and puzzles). This isn't the case with every Zelda, but for this game, we thought about the function and ability of each of the items, then came up with fun ways to put them to use.

That's something that always gives me a lot of stress as a producer. For example, once you decide how an item works, then you place stuff around the map that makes use of that ability. If you stop there, though, a lot of players won't pick up on it at all, so you need to make all these fine-tuning adjustments to the maps themselves in order to help people realize how to solve the puzzle. You don't have to take that step, but if you don't, I don't think you'd have those uniquely Zelda-like moments, where an idea suddenly comes to you, you try it out, and remarkably it works. It takes a lot of time to get this sort of balance right, to figure out exactly how much to reveal to the player first. The main keyword with Zelda's puzzles is how to provide the best experience to the player.

With this Zelda, we went back to the fundamentals. We thought about what sort of gameplay we really wanted to make. There were all these new features we wanted to implement, of course, but instead of shoehorning all of them in, we were looking for that solid core we needed in order to evolve the gameplay of Zelda. I think developing this game has helped us get a little better picture of what's really important for a Zelda title. Doing that inevitably takes a lot of time, though -- I really want to take less time for the next project, definitely."