It's definately an interesting concept, though I'm not sure who the target audience would be. The "typical" game player might find it rather boring with such a minimal amount of interaction, at least from what I saw and have read; and on the other end someone who just enjoys the story portion and not a lot of interaction might prefer just relaxing and watching a movie. It's pretty cool and I'm glad someone made it and got it out there, now it's up to the people to see how well it's accepted. It's wierd to me how some game engines are recognizable. While I was watching the 3 min "Opening Gameplay" video I thought "This really seems like the Source engine", and according to this video it is.
I think the reason why a lot of interactive story based games don't sell well is because they're basically movies. There's nothing wrong with that mind you, but who pays 60 bucks to watch a movie? This, on the other hand, is only 10 dollars with is a justifiable price, IMO.
I wrote this a couple times now: I would love to see more writers embracing the possibility of narrating their story via game engines. I can see a non-gaming, well-read, older audience, enjoying such a 'new' form of storytelling. The problem would be, making them all aware of this & having devices that would play such things (future tablets?) - or the "SteamBox" is going to be a real thing? ;)