Something that I noticed also with this game is that the levels are pretty quick to get through, if you want to play them. In fact, you even brought back time limits, and the game tracks your quickest completion time. But is that specifically for pacing on a portable gaming? And also, how did you determine what the right length of a level is?

KH: Well, this might be a phenomenon that's probably more prevalent in Japan, but of course you do see people playing games on trains as they commute to or from school or work with their portable gaming devices. When you think about the fact that it would take people 10, 20, or even 30 minutes to play one stage in Galaxy, we knew we had to limit the playtime per stage based on the fact that so many people might be playing on trains.

And so we thought about someone getting on a train and going for a couple of stations and then getting off, and decided that should be the length of time it takes to play one stage. Whether they get all the way through to the end of the stage successfully, or whether they get a Game Over, we want the playtime to fit within that interval.

And when I talk a little about the reason that we decided to go back to time limits on stages, I feel like this is something that is kind of important in an action game. You have to make these instantaneous judgments about what your next action is going to be.

It's not the sort of game where you walk around slowly and explore everything. I certainly enjoy those kind of games, but I don't feel like that's what we're going for with an action game of this type. It wasn't really our focus. So, having that time element challenge is also fun.

Could you talk about the polishing process? We talked a little bit earlier about how you will, if a level has promise, work on it. How many times might a level may go through iteration? Like, a level designer will work on it and then you test it and then give them feedback? Is that how it works? Or is there something different?

KH: Well, I think one thing that really helps a lot is playing through the level a lot. The more you do it, the better you get it, and your time starts to go down and down, and you start to realize what are the really important, fundamental things about that stage. When you're testing the level more broadly, maybe one of the important things is to get lets of different kinds of people to get their eyes on the game, so you get all sorts of different feedback.

And, again, do you source those people just from around you from your families and friends, or maybe the woman who works in the office next door, or do you do formal focus tests?

KH: In my experience, one thing I found that is really helpful is we also get a little bit of feedback from consumers when they see early versions of games at shows. That's something that I really enjoy spending a lot of time poring over the feedback from -- although it's not necessarily something that every developer does.

Do you have them fill out questionnaires?

KH: No, we don't use questionnaires. What we find is that they become too subjective. We rely more on the appearance of people actually playing the game. If, for example, you ask someone on-camera to taste something like a new food product, "Well, what do you think of it?" Chances are they're going to say, "Oh, this is really good. This is delicious!"

Just because they have that pressure of being on-camera, they give you an answer that's not entirely honest, even though they don't realize it themselves. So, what we try to rely on is more of that objective feedback that we can see in the expressions on people's faces as they're playing our games. And that's the kind of thing we've learned about from Mr. Miyamoto, who is always really focused on seeing that face, and what's the expression, and what's their reaction.

A lot of developers in the West go so far as to record the play sessions, match them with play data, and watch the eye-tracking, but it sounds like Nintendo goes a little bit more by feel, almost.

KH: Well, of course, I guess the methodology is fairly basic. You just look at someone and see what their experience is of playing the game. But you can get all sorts of information about people playing games, and you have to exercise a lot of individual judgment about what sorts of information are helpful to the development process.

And it's not the kind of thing that you can even design experiments for very well in some cases, because you might have this idea that you're going to get lots of very specifically useful information from a certain kind of test in the beginning, but once you actually try it, that might not necessarily be the case. The importance, I think, is on using what information you do get that is helpful to make the game better. That's a skill that all developers really should work hard to focus on.