The Witness aims to offer at least 25 hours of gameplay

Jonathan Blow's next game promises to be much, much larger than his critically-acclaimed Braid. The Witness takes place on an island full of puzzles. It's an open world, where you can go wherever you want.

"The island is in fact very big, for a place where you carefully visit every location during gameplay," Blow said. "Correspondingly, for a small independent team like ours, detailing this huge space is a lot of work!"

Speaking on the PlayStation.Blog, Blow says that he had originally envisioned an 8-hour game, but "The Witness is more like 25-40 hours depending on how much you play." He notes that some of the game is "optional."

Kotaku recently got to see the game at an event in San Francisco. Here's Blow walking the site through a puzzle: