It's a first-person puzzle game, made for people who like Portal or salivate for The Witness. Or for people who want to play a game that doesn't play by other game's rules nor by the rules of the real world.
In the video it may appear to strictly be an experimental first-person puzzle platformer. It's more than that. It's also a stealth Metroidvania (i.e. a game that rewards backtracking through a complex space, allowing explorers to unlock previously locked areas). And it even has a gun—a gun that works like no other gun in video games right now, but which Bruce didn't want me to show.
The game is better played than watched, but isn't that true of all games? This one, however, messes with your head. You think that falling down a pit is bad? You learn otherwise. You think that walking down a hallway forward is the same as backward? It isn't. Check out the video, and learn why I fell in love with the game.
If Antichamber looks familiar to anyone, it may be because it's been popping up in contests and at gaming shows since 2009 when it was called Hazard: The Journey of Life. Bruce dis-owns that old version and that name, which he thinks pegged his work as some peculiar art game. No, this thing appears to be the real deal, a lengthy game full of literal twists and turns that may have made me feel a little stupid but also delighted me with constant surprises, as I discovered how a new virtual world works. (We also showed readers the game when it was simply called Hazard earlier this year.)
Bruce is hoping to show the game again at PAX East in Boston in April, with a Steam release to follow (check the game's official site for more info). If you get a chance to play this, do not hesitate.