Tidalis is a block-based puzzle game with casual appeal, hardcore depth, and an addictive new "streams" mechanic. The basic rules of the game are this: blocks fall down into the board and have a color and an arrow direction. If a stack of blocks exceeds the height of the board, you lose. In order to clear blocks, you must right-click and drag paths through the arrows to set up chain reactions of like-colored blocks.
Great puzzle game based on a new, different type of mechanism. Created by the same company that did AI War Fleet Command, so expect a game that's not like anything else out there. The only possible problem, I also consider an advantage. There's an incredible number of options available that can lead to a huge variety in the game. I can see this as being confusing to some people. I think it's a great, addictive game and I'm not even into puzzle games all that much.