Valve's first-person puzzle platformer Portal became an instant classic upon its 2007 release as part of The Orange Box, in large part thanks to the game's uniqueness and charm. That makes developing a successful sequel a tall order -- if your game was a hit because it felt so new, how do you top it when there's a "2" in the title?
The Portal 2 team -- a group several times larger than the one that created the first game -- is addressing that challenge both with concepts that they didn't have the resources to include previously, and with brand new ideas that hopefully broaden the gameplay range without impeding on Portal's crucial elegance and simplicity.
In this interview, Portal and Portal 2 writer Erik Wolpaw discusses how Valve approached the notion of a sequel, how it is building on the game's established mechanics, and how former DigiPen students have once again become an integral part of the team.
How quickly did you start working on Portal 2?
Erik Wolpaw: In some capacity, we started working on it basically right after Portal, but there have been breaks along the way. The team would jump off of Portal 2 to work on Left 4 Dead or Left 4 Dead 2, which are games we shipped subsequent to The Orange Box.
Portal was a very unique game. Coming off of that, did you have particular design goals for Portal 2?
EW: Well one of the things was -- and this was early on -- right after Portal shipped, we started getting these stories from employees of Valve, who played it after The Orange Box shipped. All these stories were like, you know, “I played it with my wife,” or, “I played it with my girlfriend,” or, “I played it with my kids,” and they were sort of playing a "co-op mode" where they would solve the puzzles together. So, we knew pretty early on that we wanted to formalize that and actually make a real co-op mode.
I used to play point-and-click adventure games that way, back in the '90s.
EW: Yeah, yeah. It was a perfect game for that. We figured, “Well, there’s got to be some way to formalize that co-op play.”
That was the big initial idea. We want to introduce new puzzle elements, we want to make it bigger along that axis. Those things are sort of a given; you want to do all these things. But the co-op was the part that was like, “Wow, we’re really going to have to figure out what this means -- what co-op means.”
Did you have to go through a number of iterations of the design even to determine, on a basic level, what co-op in Portal meant?
EW: Yeah. Partly it's just wrapping your head around. It doesn’t hit you until you actually have to design puzzles for it. It’s a very different puzzle design with the two extra puzzles, especially because the co-op puzzles need to require two people to solve.
In other words, if you have a co-op puzzle that one person can do on his own, it doesn’t pass muster as a co-op. It took the designers a little while to really wrap their heads around it. Some things cropped up immediately -- they seem obvious in retrospect -- that hadn't occurred to us before we sat down to play it.
For example, there's the environment tagging. You sit down to try out your first co-op level and tell your partner, “Put a portal here,” and then you spend five minutes trying to explain to the other guy where "here" is. So some of that stuff, little stuff that again seems obvious in retrospect sort of became apparent as we started testing the co-op stuff.
[Ed.: Portal 2 features a mechanic that allows players to temporarily mark the world with glyphs indicating basic actions, allowing simple non-verbal communication between partners.]
The paint surfaces with various properties seem really similar to the IGF game Tag: The Power Of Paint. I assume they're involved somehow?
EW: Yeah, those guys work at Valve. They're on the Portal team. They got hired at Valve and they were working on some Tag stuff. Then, the Portal team was looking at it, and after a while, we thought, “Wow, maybe there‘s some way we can mix these two things together.”
We were already thinking about surfaces. There's an interesting thing in Portal where a lot of it is about interacting with surfaces. But it was kind of binary, in the sense that either you could put a portal on a surface or you couldn’t put a portal on it. And we didn’t want to make Portal more complicated, in the sense that you had more buttons that you had to hit. We like the elegance of just, “I can put portals down.”
At some point, it clicked. We realize, “Oh! If we change surface properties, that lets us do a lot of new things.” So, yeah, it was just kind of a natural fit. Again, it's obvious in retrospect, but it took us a while to come to that insight.