Designing game-based learning; what's different for e-learning designers?

It's not often that one has access to most of the leading practitioners and thinkers in the area of game-based learning, all in one place. So when I was at the Game Based Learning conference this week, I thought I'd grab a few of them and pose what I think is a very important question: "what do e-learning designers have to do differently when they're designing a learning game?". 

The responses are varied and interesting. Please forgive the video and audio quality; this was an impromptu effort with only an iphone at hand. 

I'm doing a short session on this issue at the Informatology conference in late April and a webinar for the Learning and Skills Group in May. Do come along!