Absolutely loved the presentation from Nicky Birch @birchos of Something' Else. They focus on audio only video games utilizing binaural approaches to audio design. One may seem skeptical that an audio only game wouldn't be stimulating enough or it would feel like it was missing something (picture? haha.) Quite the contrary. I like the idea of letting the listener "fill in the blanks" and form their own worlds. Granted the audio needs to fill that void a bit but I think people will be able to pick up on this concept of "audio only" quicker than they think.
Technically, there are so many new problems to solve and new approaches and workflows to explore. The challenge of telling a story with only audio (with little dialogue) sounds refreshing. An interesting point about using dialogue sparingly as it can take you out of the drama of certain experiences (getting too close to a cliff and a voice telling you you're too close, rather than letting a natural sound indicate that.)
I look forward to playing all their games and learning the techniques and approaches evolved in making audio only games.