I beta tested this game.
The Box is written in a new parser engine designed by Winters, which includes a hybrid form (like Dialog or Gruescript) allowing most of the game to be played by clicking links.
This is a literal puzzlebox. After a brief intro, you wake up in a cell with a mysterious box in front of you with 5 different puzzles or sets of puzzles belonging to each of the visible sides. Clues and aides are hidden throughout the rest of the room.
I found the puzzles generally fair and engaging. It includes a cryptogram which I generally find less engaging in IF, since they have standard solution algorithms that aren't directly integrated into game play, but I appreciated the smoothness of this one. I enjoyed the light-based puzzles and the numeric one the most, and perhaps the final puzzle.
The framing story is brief but well done. As a demonstration of language capabilities, it certainly seems like a strong parser engine, which is very difficult to do. It didn't capture my emotional fancy, but other than that it is a solid and well-done game.