People will, as you said, bring themselves to games. And not only will they interpret what they see, but they will also subvert whatever they can, a lot of the time, through their own play and experimentation. Do you like to leave room for that as well?

KS: Oh, yeah. Yeah. It's why I like making physics games, because it pretty much has that built in. Players are going to try to beat a particular area the way they want to, and they're going to go where they want to, and I think that's interesting.

Do you think systems like physics that are procedural, or not dictated by something like scripting -- are they important to games, to allow this kind of interplay?

KS: Once again I think it's a balance. It's a give-and-take, right? So you need those scripted instances. For instance, if you are really trying to teach a player something and you need, need, need to have them look at something, have them experience something, have them pay attention. I think in that aspect, it's really important. But at the same time, it's good to give room, to have the player do what they want to when you can.

And so a lot of that comes down to playtesting, and watching players play, and making sure that they're learning the correct things that they need to. And kind of being hands-off as much as possible, but when needed, putting in that heavy hand to make sure that they look at something at the right time. Whether it be locking them in a room, or taking away camera control, or something like that. If they're not going to learn something, and be miserable for the next two hours, that's bad. That's bad design.

How do you know when you can, and how much you can, do that? The "heavy hand", as you put it.

KS: Testing. It all comes back to testing. You watch players play, and if they're doing what you want them to, then you've done a good job as a designer. You've manipulated them in the correct way. But if multiple people are experiencing the same confusion, not knowing what to do, then it's us.

It's our jobs to go in and add maybe a little hint here. And then test it again, run it through a bunch of people seeing if the same problem crops up again. If it still does, then add a little bit more, and a little bit more, and keep iterating and testing. And that's how our whole game was designed, essentially. It's just like... yeah, you have an idea of what you want, but you won't really know if that idea is successful until you actually test it.

Would you say you've done a similar kind of testing as you did with Portal?

KS: Yeah. Basically we run through somebody hasn't played before at the end of the week, and play them through new puzzles that we haven't seen playtested before, and see what worked and what didn't. And then immediately going back in and iterating on top of what we've learned.

How long is the cycle on this game?

KS: We're clocking in a little under a year. And we have a team of 16 people... No, we're 17 now. We're 17 now. And yeah, just, small team, small budget, small amount of time.

Do you like keeping it small and fast? Is that what appeals to you most?

KS: I like everything. I don't know. I don't have a particular preference, but in the case of [Quantum Conundrum] this is a new IP. It's good to test the market to see if this type of game is still viable, and if people want to play. So I think in this way it's a good way of hedging our bets. It's like, okay, we know that we can do this in under a year, put it out there, and see how it resonates. And whether or not you go big, stay the same, don't do anything at all... Who knows? So we're crossing our fingers that it'll do well.

The thing is that you hit much bigger with your first commercial project than you probably could have ever anticipated. Not even necessarily commercial success, which of course is one thing, but also it became the inescapable part of the gamer lexicon for the next more than a year. Everything from Still Alive, "the cake is a lie", the Companion Cube -- everything. A lot of people on Earth could, I'm sure, but I certainly couldn't have a conversation without some of that stuff coming up on a daily basis.

KS: Yeah, and I guess, from my perspective, I took what I learned from Portal, and am trying to apply similar practices of things that I feel worked, for sure. It's like, learning good lessons and then immediately throwing it out the window, because like, "Oh no, I'm copying this other thing"? And it was just like, why?

At the end of the day, I want to make products that people have a good time with. If players are having fun, then I've done my job, and I try to not get weighed down with the idea that I have to compete with myself. It just seems silly. I'm making games. It's not like I'm making like the cure for cancer or something. Like, I cured breast cancer, now I'm curing prostate cancer, right? It's a game. It's meant to be fun, and for players to have that moment of escape, and time out, in their lives -- to have a good time. And so I just take that for what it is.

This game is lighthearted, at least from what I've seen. Is that important to you, too? I know Left 4 Dead wasn't lighthearted, but I don't know how much oversight you had into the creative direction. How do you feel about that kind of thing? Because, obviously, so many games are so grim.

KS: I guess, for me, I wanted to do something different. I miss the days when it was okay to have a stylized game, and it wasn't immediately branded as, "Oh, this is a kids' game." No! What happened to the '90s? There were cartoony games, and it was okay! And so I miss that.

As well as, I think it fits the gameplay. I mean, there's a fluffy dimension! Can you really picture that in a realistic style setting that's grim? It's like, yeah... not so much. And we did do some iterations at the very beginning, trying to play around with different looks and feels for the game, and this is what we all ended on as a team, and really liked it.

What comes first -- the fluffy dimension, or the cartoon look and feel?

KS: Dimensions came first. So for me, my principle is gameplay should always come first, because, at the end of the day, it's a game, and it's all about that interactivity with this world. And so I don't care how awesome the art looks. If it doesn't play well and it's not fun, then, meh.

Yeah, we definitely prototyped it right off the bat -- and it was not a pretty looking game -- and got the dimensions, a couple of them, up and running right away, and started playing with them, and seeing if there was potential.