I'm wondering how you would... I heard the possibility of expansion or something like that. How could you keep going in the Portal world?

EW: There's other avenues to explore. We haven't announced anything yet. We're definitely thinking about what comes next, but we can't really talk about it at this point.

Okay. Well, I'm not trying to get secrets out of you.

EW: That's all right. It's your job.

Well, not necessarily. I'm just trying to think... since GLaDOS is dead and stuff.

KS: Well, the title of the song is "Still Alive."

EW: Yeah, she might still be alive.

That's true. So it's something you actually want to revisit, instead of something different?

EW: We like the world of Aperture Science, and we'd like to revisit the world of Aperture Science in some form, whether it's GLaDOS or Chell or something else. But Aperture Science seems like a rich environment for this game to take place in.

Do you have any plans or hopes to do something beyond, or other than, that?

KS: You mean like work on other games at some point? Well, obviously. There's only so many sequels we can make.

EW: The good thing at Valve is that everybody's got their hand in different things. I don't know how many projects Valve has going on right now, but it's a fair amount. You can bounce around and help out here and there, which helps alleviate the grind you get into of doing one thing over and over again. You can spread yourself out a little bit.

Since the process is different... someone made a comment at DICE a little while ago that all of the biggest blockbusters of this year, and in fact through the 2000s, were delayed or took a long time. Do you agree? What do you think that says about what people are doing?

KS: I think that means that they care about their players, right? You don't want to send something out the door that you don't have faith and confidence in. It's not a great thing to do.

EW: Before I worked in the game industry, I was a database application programmer. It was exactly the same thing. No project that we ever worked on shipped on time, so it may just be a software thing. I know there's lots of theories about it.

Movies seem to come out and be produced more or less on time. When a movie is delayed significantly, it's big news. I think it may be a software thing, and something to do with software.

Games do come out of that, it's just that those aren't the ones that are awesome a lot of the time.

EW: Putting extra time into something... I was going to say "makes it better," but that isn't actually true either.

KS: Well, it's more like, "making sure that you're ready."

EW: Did Call of Duty 4 come out on time? Was that delayed? When people don't announce dates, it's hard to tell.

I think that was probably Call of Duty 3, originally, but Activision was like, "We need a Call of Duty right now."

EW: So what we need to do is less of that. "We're not coming out until we're ready."

I think they do that for investors. With the movie example, it's because there's a much more established process, and in games, everyone's doing stuff in their own way, and the tools aren't integrated or the same across the board. There's so much noise that has to be clipped out first.

EW: I think so, yeah. All those factor into it. But again, it's like the database applications. Nobody seemed to be able to deliver those on time. I don't have smart ideas about it, except that...

KS: To not announce it until the last minute?

EW: It's endemic in any software undertaking. There's something about writing software that causes delays.

I'm curious to know -- this is also tangential -- how did Mike Patton get involved with Portal?

EW: He does the zombie noises for Left 4 Dead, and he had recorded like a two-and-a-half minute demo for us. It wasn't like we were auditioning him. We just wanted to know what he would sound like. We had Ellen originally do the anger sphere, but she was just too nice, and couldn't quite pull it off.

I was panicking at the last minute, and just happened to be doing some of the Left 4 Dead stuff, listening to the Mike Patton voice, and I was like, "Oh, we should use this!" So then we had to go through a little bit of union stuff, and we were eventually able to buy it and put it into the game. I don't think he even knows.

KS: Yeah, he knows.

EW: Does he? Okay.

He probably played it.

EW: I don't know about that.

Really? He does play games.

EW: He may have played it, then.

With Mr. Bungle, he used to do Super Mario Bros. stuff.

EW: Oh wow. He may have actually played it then. He was excited about Left 4 Dead.

I think that's why he's doing more voice acting now. He's the protagonist in Bionic Commando.

EW: Oh, that's right. He's got a good voice. If you need somebody to make monster sounds, he should be your go-to guy. He's just a savant at that stuff.

Not that you would ever do it, because it's not really Valve's MO, but do you think Portal could work on a handheld, like on the DS?

KS: That could be cool.

EW: Somebody made a Flash game that was pretty clever 2D implementation of it. Yeah, I think it could. I'd love to attempt a DS version, but I don't even know what the process would be to get that going. I guess we could ask Gabe. I think it would be neat. People would like that on the DS.

KS: I know I use my DS all the time.

I'm pretty sure that Source is not running on the DS right now.

EW: No. I don't think I'm giving anything away by saying that it is not.