What they've created is one heck of an experience. The concentrated story that I saw at GDC has grown into a gorgeous, expanded universe for your Superbrothers-style warrior to explore and interact with, and the game plays like an interactive piece of art, with mystery and magic around every turn. It's a game that's hard to categorize; there's not much text, and what's there is pretty incoherent, with phrases like "she knew whence we had come," and a quest for a book called the Megatome. When I asked Vella what genre he considered the game to be, he said it was "inspired by old-school adventure gaming, but we call it an exploration and experience."
The basic mechanic is this: touch. Almost everything you touch in the world reacts in some way -- if you touch plants or animals, they will shake or run and hide. You can drag to move your character, or double-tap to send him around the screens. The general theme is exploration -- find caves, meet people, and learn about the world you exist in.