At yesterday's Reboot Develop conference in Croatia, Jonathan Blow showed off what he's been working on during his talk on programming.
During his talk he showed-off a puzzle game where your character pushes blocks around a grid. Blow added that what the crowd saw at Reboot isn't 'remotely final,' before playing with the code and changing elements at will.
Blow added that he's mapped out approximately 25 hours of single-play content for this unannounced block-pusher.
If the gap between Braid and The Witness is anything to go by, we mightn't see much more of this for quite some time, so enjoy this little smidgen of info. Check out the archive of the talk from the 5:32:11 mark to get a glimpse into Jonathan Blow's next project.