Preview: Portal 2

"Oh, it's you. It's been a long time. How have you been? I've been really busy being dead. You know, after you murdered me. Okay, look. We both said a lot of things that you're going to regret. But I think we can put our differences behind us. For science. You monster."

Both Portal and its slightly unhinged antagonist GLaDOS are back in a sequel that hopes to do more than "just extend the original game" according to Valve's Erik Johnson. "If you ask fans what they wanted, they'd say they want more Portal 1," Johnson said. "But we felt like what they're saying is that they want to be surprised again." While the addition of a co-op experience may surprise you, there's a lot of comfort food here. Not only is GLaDOS back, but so is protagonist Chell, the (slightly worse for wear) Aperture Science facility, and the game's now trademark sense of humor.

While laying out the three major focal points for the game – that's story, gameplay, music if you're keeping track at home – Johnson explained, "The story needed to be funny. It needed to have a lot of the same characters. You're playing as Chell in Portal 2. GlaDOS is back. And there will also be some new characters, one of which you'll see today."

That one is Wheatly, pictured above. "He's this little personality sphere and he's been trapped here for all this time also and he's going to help you escape the testing facility," Johnson says. In the short segment with Wheatly that we saw, the English-accented ball cracked wise while helping you advance. After inserting Wheatly into a module on the wall and turning around – "I can't do it if you're watching" – he opens a "secret passage." When an automatic turret says "hello," Wheatly responds, as if addressing a beggar, "No. No thanks, we're good." That injection of humor and unique characters creates a much different, less solitary feel.

Another story-related element that changes the feeling of the original is the changed environment. Gone is the sterile Aperture Science from the first game; in its place is a dilapidated overgrown structure. "GLaDOS is, at least from her perspective, kind of tidying things up along the way so she can get back to testing you," Johnson says. It's immediately recognizable as "Portal" but it's different enough to provide a new experience.

Similarly, the gameplay will be immediately recognizable, but there's some new "characters" there as well. Joining the portal gun are plenty of environmental puzzle elements. Take, for example, the springboard or, as GLaDOS calls it, the "Aerial Faith Plate." Step on it and launch Chell across the level. Or the vacuum-like "Pneumatic Diversity Vent."

Particularly interesting are the "gels": the flubber-esque "Repulsion Gel" and the boost strip-esque "Propulsion Gel." Johnson says, "In Portal 1, surfaces in the world have two states: You can either place a portal on them or not. In Portal 2, we're adding these different types of gels and those get placed on the surface." Imagine a puzzle where you use a portal to redirect a spigot of Repulsion Gel to coat a surface. Then, use another portal to fall out of a nearby wall, bouncing off the gel, reaching high areas. Or redirect a spigot of Propulsion Gel to coat a surface, run on it and make a loop to really boost your momentum before firing a shot somewhere else and redirecting that momentum over, say, a deadly chasm.

There's also a traction beam, an energy bridge and, one can only imagine, plenty more. Any one of these provides ample puzzle fodder; the combination of several of these creates what could only be described as a puzzle-splosion, as evidenced by a short montage at the end of the demo. But that doesn't mean "more difficult," Johnson insists. "The important thing for us is to make sure we're not building a game that's more difficult or requires some skills, like in an action game." He also says that since the game is "a lot bigger" it offers the designers more opportunity to introduce gameplay mechanics, master them, and then combine them.

That challenge of trying to keep the single-player game from being "more difficult" didn't apply to the co-op component. "Those levels are quite complicated, pretty challenging," Johnson says. While the first Portal was a strictly single-player affair, Valve learned that many players played it as though it were co-op. "A parent would watch their kids play or two people would sit on a couch and play together. "

Last, but certainly not least, is the inclusion of Steamworks support in the PlayStation 3 version. While it's not clear to what extent Valve will be able to integrate its PC gaming suite on the PS3, Johnson says that, "Right now, for sure, matchmaking and achievements and updates, especially updates" will be on the PS3. When asked about cross-platform matchmaking between PS3 and PC, Johnson said, "We don't know that yet. There's nothing technically that stops that, and we think it would make a lot of sense. I can't see any cases where it would hurt."

If you, like many of us at Joystiq, were worried that what made Portal 1 so special would be lost in development of a sequel – think of all those awards and memes and plushies – then set those fears aside. Portal 2 isn't just "more Portal," like Johnson said. It's surprising. Again.