Portal only lasted about four hours, but it's left a greater impression on the gaming community than many 20-hour-plus blockbusters. Is Portal 2 being deliberately kept short to preserve some of the original's feel, or will we see a longer game?
The game is considerably longer. The single player is about two-and-a-half times longer than the original, and then there is co-op, which has an entirely separate story and maps and lasts twice as long as the original itself. With Portal 1, our goal was to step you through all the cool things the portal gun could do with as little repetition as possible. That resulted in a four-hour experience. We applied the same goal to Portal 2. However, given the combination of all the new test elements, the experience just naturally ends up being longer than Portal 1. In other words, exact same design philosophy + expanded puzzle space = longer game.
Do you think that a Portal sequel is risky because of how well received the original was?
There are no bigger fans of the original Portal than the Portal 2 team. As the game was expanded with new puzzle elements, characters and locations, we all worked hard to make sure the original feel and attitude of the original was maintained. At the beginning of the project it may have felt risky but as we approach release we are confident it was the right choice and that fans of the original will love the sequel.
Portal 2 will have a separate co-op campaign. What can you tell us about it?
Portal 2 co-op expands the Portal 2 world. It has its own story line and introduces two new characters, the co-operative testing imitative bots. The puzzles in co-op are also specifically designed to always need two people to solve.
If you don’t have a friend in your house to play split-screen with you, you can also play online including cross platform play between PC, Mac and PS3.
The game's website has a number of teaser trailers showing some rather exciting footage of new game mechanics. Are there any that you would like to talk about, and are there any unrevealed gameplay elements you can tell us about?
Instead of discussing individual elements, I think the important thing to take away from those teasers is you will be able to do that! It is hard to imagine starting out that you will be able to pull off all those moves and combine those elements, but by the time you reach those areas in the game you are so well trained you can. The hardest part is not doing the activity to solve the puzzle, but instead thinking through how to solve the puzzle.
This was an important point for us on Portal 2. We wanted to add complexity without adding difficulty. If you could understand the puzzle and know the solution, you could solve the puzzle. The puzzles do not rely on your ability to manipulate your input device but instead your ability to solve puzzles.
What can we expect in terms of modding support for Portal 2? What about cross-platform modding?
After release we will make the SDK and level-editing tool hammer available on the PC platform. The content created with those tools will instantly be available for users on the PC and Mac. Xbox and PS3 users will have access to this content if we package it up.
In Left 4 Dead 2 we are currently having our first test of moving community-made content over to the consoles. We will take what we learn there and apply it here.
Tell us about the cast of characters in Portal 2. Was the choice to add more speaking parts a hard one?
The choice to add more speaking characters was easy. At Valve we playtest and get feedback on all aspects of our game. One of the most important pieces of feedback was on pacing. As we expanded the length of the game we wanted to make sure players did not become fatigued by any element.
So that players did not become exhausted by Glados we wanted to create a character that played off her measured delivery. Wheatley, voiced by Stephen Merchant, is the exact opposite of Glados. He is a fast speaking character that talks before he thinks. His voice and character are the perfect break from Glados and he isn’t the only new character...
What about the Portal franchise overall? Where will it go from here?
We like to concentrate on the project at hand. Right now we are still finishing up the PC/Mac version of the game. Once we are done there, we have some ideas for DLC, and after that? We will take feedback from the community and see where Portal goes from there. We do love the world of Aperture Science and imagine spending more time there in the future.