I noticed also in the presentation that you gave the game to your son and saw how he reacted. There have also been discussions of similar things. Mr. Iwata discussed how Mr. Miyamoto would kidnap employees and make them play the games. Do you do formal playtests with focus groups, or do you rely more on small tests with friends, family, and co-workers?

KH: Very often we will do our playtesting with family members of our staff, but it really is a case-by-case basis. For example, in the building next to ours in Tokyo, there was an older woman who was an office worker, and we had her do some playtesting for us.

But what we realized was that she had a lot of trouble jumping across even a small gap. We thought, "Maybe if we give her the Tanooki Mario suit, she'll be able to do it if she's just right at the very edge." But there was something she struggled with so much.

When we eventually had her use the P-wing to get to the end of the level, we thought, "Well, okay, she got through to the end of the level, but what we really wanted to see was her being able to jump this gap." And so that's the sort of thing that made us realize we need to put in some access to the Tanooki suit a little bit earlier, if people are having a particular amount of trouble with a certain stage.

And that led us to the White Tanooki Mario suit, which gives players invincibility, as well as the ability to slow their fall after a jump, so they can make their landing easier.

You talked about how Mr. Miyamoto put the P-wing in Super Mario Bros. 3, and so you did something similar. Obviously, hardcore gamers look down on this kind of thing.

KH: I guess I would have to say, first, that in my experience I've seen hardcore gamers who try to play the game so that they never let the assist block appear at all, as if that was their goal. You may have noticed that you have those stars that appear next to your save file, you can get from one to five. If you play so that you never make an assist block appear, then you'll have five stars that are sparkling. And I would like to engender this mentality that if you can't do that, you can't call yourself an advanced player.

Do the less experienced players really enjoy this stuff, and have you found detailed feedback that these things really help them get into your games? And as Mr. Miyamoto said regarding Super Mario Bros. 3, maybe go back and challenge the levels once the stress of completing them is taken away?

KH: Some people on our development staff felt like having to die on a stage five times was even too much before an assist block would appear. They wanted us to lower it to maybe just three misses. But when I look back at, say, New Super Mario Bros. Wii, I believe you have die eight times before you would be able to see the Super Guide.

But there are definitely those people on staff who suggested that we keep placing it earlier and earlier. But I'm a gamer, so it's hard for me to imagine people wanting that.

But as it turns out, there are some people who might've been happy to play through a level for their very first time as White Tanooki Mario, just being invincible and focusing on the platform challenge. So, when I'm thinking about how we design games, I have to include those people in my thinking, too. I can't just write them off completely.

Talking about level design, obviously the level designs in Mario games are polished -- very perfectly, so they perfectly fit together. If a design isn't working, are you more likely to try to refine it, or do you actually discard things that aren't working?

KH: Well, we mock up stages very early, and these are very rough versions that we'll try and play through. And if something's bad, certainly we'll throw it out. But if something shows a bit of promise, we'll hold onto it and keep polishing it.

Speaking of holding on to things, I noticed in Galaxy 2 you have the level from Mario 64, and that's the same level you used to test in 3D Land. Is there something special about that level specifically?

KH: Yes, I guess we do keep using that as sort of our standard test for each new generation. I think one of the reasons for that is because it's a floating island -- the entire stage layout -- so that makes it something of an easy test case in terms of processing. But, of course I can't rule out the fact that I also just love it as a playable course.