Shade

Very well written -- moody, evocative, and not too heavy-handed -- but I found steadily declining pleasure in it, especially once I got to the (Spoiler - click to show)fiddle-with-every-damn-object-until-something-happens section. Eventually the puzzle-solving part of my brain checked out and went on vacation somewhere, leaving me to go look for a walkthrough.

It didn't help that I saw the plot twist coming from the minute I saw (Spoiler - click to show)sand.