Braid and The Witness developer Jonathan Blow has revealed a very brief sample of the upcoming game he's working on.

Teased during his talk about programming at today's Reboot Develop conference in Croatia, Blow offered a brief snippet of the engine he's created over the last year for his upcoming game, which appears to be a puzzle game with some degree of block-pushing.

"It's a nice little grid-based game," said Blow. "I've got a guy who can run around and push blocks and stuff."

Seen at the 5:32:45 mark above, Blow noted that these visuals "aren't remotely final."

Blow said that he's already created about 25 hours worth of single-player gameplay for this unannounced title. Now what could it be?