This is indeed seriously impressive. I keep wanting to keep my entire knowledgebase on a canvas so that I can "think" or navigate spatially. Thisis neat.

In the main landing page, as I was clicking around, I kept wishing to have a legend to show me either "how deep I am" or "how do I get out of here?", and like someone else commented, I would love an affordance showing me what was clickable/zoomable.