IGN: It looks like portals can be created on hard stationary objects. Can portals also be created on soft bodies or moving objects?

Kim Swift: Portals can be created on any flat surface that is large enough for one of the portals to fit on: walls, floors, and ceilings. There is currently not an implementation for placing portals on moving surfaces at this date.

IGN: Will most of the puzzle challenges involve logical thinking as well as twitch shooter gameplay, as some of the later clips hint at? Will there be a hint option for those of us too stupid to figure the puzzles out on our own?

Kim Swift: We believe that it's very important to bring in a playtester every week to test through the game and this lets us know that the levels we create are reasonable. Doing multiple iterations on new content as soon as possible helps us ensure that players will have fun. In addition, like Half-Life 2 we have difficulty settings that will scale damage, accuracy of antagonists, etc.

IGN: Valve seems intent on creating smaller, more bite-sized quantities of content, the direct opposite approach that took place in Half-Life 1 and 2. What is Valve's strategy right now on episodic content? Will we see more? Are Episode 1-3 an experiment or they part of a long-term strategy?

Kim Swift: Because of episodic content, Valve has been able to take risks on games like Portal. It would be pretty dangerous to go and spend $10 million working on a brand new game mechanic, which is why lots of games tend to stay pretty close to what's been done before. With Portal, we have a small team working for a year, and we get to release it and hear people's reactions without having to take all the risk involved with a monolithic, multi-year, multi-million dollar project.