At the Experimental Game Design lecture (where, among others, we heard from Crush's Alex Butterfield), Valve's Kim Swift, one of the designers of Portal, talked about the challenges of creating a first-person mind-screw puzzler, which is packaged with the oft-delayed Half-Life: :Episode 2, Black, and Orange sets, and concluded with a video demonstration solving one of Portal's crazy door-opening puzzles.

"Doing something new can be a really big risk and adding something innovative to something already exists can often disrupt and create new games," she said. Swift told the crowd that she and the team approached Portal problems as small gamelets in isolated environments. To her, trying to innovate too much at one time can lead to failure. Jurassic Park: Tresspasser, she quipped, is an example of a title that "tries a lot, and fails at all." Swift's mantra is to try one thing and polish it to the best of your ability.

Following her talk, Swift started a video of one level of portal to explain the depth of the puzzle. In Portal, you can make a blue and orange-rimmed portal that interact with one another. You can attach a portal to most surfaces, although reflective and glass surfaces will not take a portal, "just to make your life more difficult," Swift notes.



The demonstration begin with the computerized female voice assuring the crowd that "if you feel light-headed, feel free to pass out." To solve the puzzle, which involved having two buttons pressed down to keep a door open, the character placed a portal in the path of an energy ball to make it pass through onto an activator which started a platform that helped you to shoot a portal near a crate to fall onto a switch, whereby you portal yourself onto another switch and proceed to create a portal behind the now-open door so that once you get off the button you will be in the clear. Still with us? Good.

Then came the goofy part of the demonstration. Swift's character placed the portals perpendicular from one another and sent a crate continuously moving at an angle between the two. Then two portals side by side, so as the crate can bob between the two. Then the character created a portal above and below one another, recreating the infamous "infinite portal abyss" move.

We'll have more from yesterday's Experimental Game Design lecture later today.

This article was originally published on Joystiq.

GDC 07: Super Paper Mario impressions