We just came out from seeing Portal 2 being closed doors at E3, and it looks extraordinary. Without further ado, here's what we saw.
The demo starts with a look at what's happened since the last game. GLaDOS was defeated, and Aperture Science was in ruins. Now, you play as Chell again, and GLaDOS is back. But Aperture Science is rebuilding.
In the demo, you meet one of GLaDOS's personality spheres, a brit called Weylan. Think of him as a sentient Companion Cube. He's funny and clever, but shy. In one small piece of brilliant comedy, he won't plug himself into a particular piece of machinery until you turn round. "Don't look!"
The lighting model has been significantly improved, as have the textures of the world. Whereas Portal 1 was clearly a fairly low-art project, Portal 2 is of the same art and graphical quality you'd expect of, say, a new Half-Life 2 episode. There's also a fluid dynamics model added, and better physics simulation.
There a bunch of new problems and solutions in the game, but the fundamentals of how you interact in the world are exactly the same. You fire entry and exit portals, and you pick up and move objects. There are no guns, no buckets of paint. It's still the same old Portal. Here's what's new:
Great globs of liquid fall from pipes, and they change the way you move. Yellow paint makes you move at great speed. Blue makes you bounce high into the air. You spread them by placing portals under their exit pipes, and they slosh around beautifully. The fluid dynamics are startling.
Now you can jump into a floating tractor beam, or as Valve calls them, the 'excursion funnel'. If you place your portals right, you can divert them from their original path.
They were used as a comedy way to suck up turrets - just turn their vacuum to the exit of a portal. At one point, the vacuum tubes sucked the panels off a wall.
Used to divert lasers, and to cook the little turrets. "I'm burning!" they cry, as they slowly toast.
Valve's Erik Johnson explains that they "wanted to make a bigger and better game, but maintain the Portal feel that players fell in love with." He also said that the game "won't be significantly harder, even despite the additional mechanics."
What we saw was a behind-closed-doors demo, so there's no footage of that. But here's the new E3 trailer .