Lettres Volées ("Stolen Letters") is the kind of game you can't write much about without giving spoilers. Let's just say it's a game in which you're not moving in space but in time. That's very rare in IF, despite the fact that time tracking is well-supported by Inform, at the very least.
Essentially, we're talking about a one-room game where descriptions change constantly. As time passes, you remember more relevant information about the surrounding objects, and you're offered more things to do with them. As a nice touch, the location itself is only described indirectly, through said objects. Artistically speaking, this works very well. Lettres volées does a great job of setting a mood and making an indirectly-discovered world come to life.
On the minus side, what I'm supposed to do in the game is despicable. I had to turn to the solution to even realize what was expected of me, and I still don't understand why I should be interested in doing it. And what's with all the waiting? I know there's a reason for it, but the third or fourth time it's no longer funny. Either I'm not on the author's wavelength, or else Lettres... needs a lot more clues. And I mean in-game, not in the hint system!
I could not reach the end in time for the voting deadline, (or afterwards, for that matter) but I hope to return to it someday, if only to see what other surprises the game has in store.