Well... let's start with the positives... It uh... looks nice, I guess? Scratch that. Graphically, the game is impressive, but it doesn't look nice per say. The art style is rather dull and desaturated, which a Thief game would never be aesthetically. Thief utilized the varying light as a design choice, so dark areas like dimly lit rooms, caves and caverns, etc... appeared to be pitch black. But when you entered a well lit area, you noticed how vibrant with color and detail everything is. In this new Thief, it's harder to distinguish what is dark and what is bright. I find myself confused at moments when the light gem alerts the player that he is concealed in darkness, yet there is hardly any so called "darkness" to be seen. Then again, the moments where areas are illuminated seem too dark and dreary. One good counter example to this style is Splinter Cell: Chaos Theory. Most of the time, you wear your night vision, because it's difficult to see in the darker areas while infiltrating certain enemy lines. So, say you are in a dark area and your light meter says you are practically invisible in the shadows you've found refuge in. When the night vision goes off, it's clear that you are in the shadows and no one can see you, the only indication of where you are being the artificial lights on your character's suit. In the new Thief however, as I said before, everything just seems grey, with no real contrast or dichotomy between light and shadow. I still haven't watched the full video, so more is yet to come out of me. I'll give my next couple of thoughts once I see the game play.
