What about the lack of speech for the protagonist? Was that completely intentional, or was that just a byproduct of this?

KS: We wanted to keep the Half-Life 2...

EW: Yeah, once we were going to tie it into the Half-Life universe, one of the conventions of the Half-Life games is that the lead character doesn't talk. But the general atmosphere of Portal made it so that it sort of made sense. The main character wouldn't ever need to say anything.

KS: Unless she wanted to talk to herself.

EW: Yeah, she'd be more or less talking to herself. It was a conscious decision, but we made that early on, and it was never anything that we agonized over too much.

I was expecting her to either start talking to herself or have hallucinations about the companion cube talking to her, or something, because there kept being references to it.

EW: That was a debate we had. At some point, we'd had the companion cube saying something, but eventually, we just decided that it was stronger that it was hinted at, and it never actually said anything.

KS: Though you do see it at the very last FMV sequence at the end of the game. There is a companion cube.

EW: Yeah, he's there. Silent.

Do you think this kind of level of narrative could be achieved with a protagonist that speaks? Is it possible for the player to relate to that character?

KS: I have no opinion.

EW: I think it could. The less simple you make it, the more you risk increasing that delta between two stories, which is a harder problem. We optimized for keeping that delta low, and one of the ways we did it was by keeping the protagonist silent.

That was the only thing where I was like, "I wonder what would happen if they tried this?" It was already advancing things, so I was wishing that you could figure out how to do that, too.

EW: It may very well have worked, but like we said, it was one of the things we decided on early on, and we never saw any need to worry about it.

I didn't mean necessarily for Portal.

KS: I don't see why not.

EW: Oh yeah, you could make it work. I can't imagine why you couldn't. I'm trying now to think of a game with a non-silent protagonist that works really well.

That's the thing.

EW: For shooters -- Portal's got that shooter viewpoint -- I tend to prefer games where I don't...the main character isn't speaking. Part of it is just a practical thing.

KS: It's distracting.

EW: Well, it's distracting, but also because I can't see the character, sometimes it's confusing to me who's talking.

KS: Yeah. "Was that a dude over there, or was that my character?"

EW: In Portal maybe it wouldn't have been as big of a deal.

KS: There aren't any other characters.

EW: But still, who knows.

Did you play King Kong? It's actually pretty good.

EW: No. But I did play the demo.

You should play it. It's all right. It's a good realization of what, in my opinion, all those Sega CD FMV people were trying to do back in the day with movies.

EW: So is it first-person?

It's first-person, and he talks sometimes. You can tell just because of the way they do the sound phasing and stuff. It sounds like it's coming from here, whereas all the other characters sound like they're coming from over there.

KS: Interesting.

EW: You could definitely make a game where you do that. The Half-Life games, and Portal especially, again, the main character is just a player surrogate. It's sort of a cipher. It's a complete blank slate you impose your own viewpoint on.

The two hour total playtime, was that a target, or was that just a result of how much you felt you wanted to put in?

KS: It was pretty organic. We didn't really have, "Oh, we need to hit two or four hours." The length of the game mainly came out of our playtesting. Actually, the ironic thing was that the better we tuned our game, the shorter the game got. (laughs)

It was kind of sad for a little bit, but it gave us enough time to give us a good story arc and get to know GLaDOS, and weave the game with a sense of accomplishment and learn this new tool. We thought it was a good stopping point.

How has the reaction been to the length, from your perspective? I thought it was good.

KS: We get mixed reactions. Some people are like, "Oh my god, what are you doing?" and other people are pretty appreciative, especially in the game industry, I think.

EW: Yeah, or in adults. They're constantly referring at Valve to people who really think a lot about games and play games, and many of my adult friends never, ever finish games anymore. Like, they don't finish them. We just thought it would be nice to have a game where, if you play it, you probably will finish it, unless you just don't like it.

In direct opposition to your mixed feelings about how people are reacting, I'm surprised at just how positive the reaction has been, or what a non-issue, in a lot of cases, it's been. At two hours, I think a lot of players are more dedicated to it. In Steam stats, it's more like three and a half. Regardless, though, it's still short.

Although it seems to be a trend. In Call of Duty 4, the single-player is awesome, but I think it took me five and a half hours or something. So it's not super-long either. That seems to be the trend. BioShock was pretty long, but it almost seems like a throwback, in how long it was.

Yeah. I have finished Portal and Call of Duty 4, but not BioShock, even though BioShock is awesome.

EW: That's the thing. There's a practical constraint on time for people who aren't 14 years old. You just can't spend that much time playing a game, so is it a good thing to have games that people eventually just get sick of before the end, or run out of time? A lot of games I would like to come back to, but there's this barrier of reentry, in which I don't remember what the hell I was doing a month ago.