I just did some updating to the wiki on The Witness page. Today was the first time that I have heard about the game, but it looks beautiful and the mechanics intrigue me. The game is set to come out on PC and PS4.
Jonathan Blow said in an interview on the Playstation.Blog, that The Witness was going to be an open world puzzle game. Now, with the puzzles being attached to doors and things that probably hide keys, in the same vein that Myst did it's Open World Thang, I am convinced that the world will have open world aspects but also be shuttered in many ways too.
The only thing that has me a little worried is that Blow said he went out to make an 8 hour game, but this game is more like 25 - 40 hours, depending on how long you want to meander in this type of scenery. Now, I will spend 25 - 40 hours playing Plants vs. Zombies. I will even spend 25 - 1000 hours playing games like Tetris, Lumines, or Puzzle Quest. I am worried that this game is going to have too much story to keep me interested in a puzzle game for 25 - 40 hours. Puzzle games are intrinsically 'pick-up-and-play.' Braid had a lot of story chocked into a pretty short game. I hope that this game is able to keep me interested for such a long time, or the story is accessible enough that I can enjoy this game at a leisurely pace.
I'm excited to see what this game is all about. It looks like it could be a beautiful game to play. Jonathan Blow has proved that he can make insightful, fun, nostalgic games once. Here's hoping he can bring back those elements in The Witness. I just hope that he can bring some other elements in since this game is stacking up to be 2 - 5x longer than Braid.