6 Differences
It's probably either dark or getting dark where you are, so it is or is almost a good time to play 6 Differences. It's the elemental puzzle find-the-differences, but it's stylish and animated and oh so pretty. Use the music option. Try shaping your browser window around it, with a dark desktop or Isolator, even.
(If you care about Kongregate you can play the Kongregate version for a badge when you complete the game.)
Comments
I'm not sure if it's the same developer or not.