The submission links to an update on their Kickstarter page where they first explain what it is before linking to it. If you want to go straight to the demo, this is the link you want:
We had a lot of fun prototyping this, and it's just the beginning. Each time the Kickstarter pledges reach another $100k, we'll release another iteration based around fan feedback. This could mean better art, sound and narration, expanded gameplay, death sequences, etc - we're really looking to just interact with the fan community on this.
As far as we're concerned, getting to do this (working with our childhood heroes while using our favorite development platform) is a net win for hackers and geeks, so I thought it would be a relevant post here. Have fun!