Transmission is a puzzle game about communication networks. Created for London's Science Museum, it charts the history of telecommunication through their connections—showing the increased complexity of every new development. It starts with telegrams, then telephones, then computers, then broadcast, then... well, I don't know, I haven't got that far yet. Maybe MySpace?
At its most basic, you need to move information from a transmitter to a receiver—dragging a connection into existence between the two nodes. As you move through the technology, the amount of information that can be moved increases, but so does the complexity of making that happen.
It's neat—relaxing, with a nice tactile pleasure to drawing out connections. It does take a while to become taxing. You should breeze through the telegram and telephone phases, with things not requiring much thought until the computer phase.
You can play Transmission now, for free in your browser, by visiting the Science Museum website (opens in new tab). For more info, head over to the game's official web page.