Valve showcased their new Steam Controller few weeks ago, but nobody knew how exactly it works. So steam has now posted a video to demonstrate the how this unique controller would work.
In the demo they used the controller for various famous games like Portal 2, Civilization V and Counter Strike : Global Offensive.
Looking at the demo its safe to say it’s still in the developing phase and this one would still be a prototype they are testing. As described in the demo, the controller is a straight replacement to the legacy keyboard and mouse controls unlike other game controllers which work completely different and have a different setup when you use them.
Valve has promised more similar controller demos and some game footage which would be played by the game developers itself.