One of the neat things about Valve's Steam Controller is that it will work with any mouse and keyboard-controlled game. This opens up Steam's entire game library to work with Steam Machines, due out in beta form later this year to run SteamOS.

Valve has released a demonstration video showing how the Steam Controller works with games like Counter-Strike: Global Offensive, Portal 2, and strategy game Civilization 5, which have not necessarily been configured for the Steam Controller yet. The video shows how the controller is a bit more comfortable on a couch, instead of a keyboard and mouse. The Steam Controller even includes a number of specific controller schemes - "legacy mode" controls in Portal 2 are shown. Check out the video - the track pads are interesting, too. 

Valve took the wraps off its plans to infiltrate the living room last month with the introduction of SteamOS, Steam Machines, and the Steam Controller. The Steam Controller will ship with the Steam Machines beta to 300 participants by the end of the year. Several hardware manufacturers have been tapped to launch a slew of SteamOS devices in 2014.

Valve has yet to reveal a design for the Steam Machines beta, but it will be a concise 12 x 12.4 x 2.9 design. The prototype will be fully upgradable specification wise. It sounds like Valve wants you to tinker so they can understand the full capabilities of SteamOS, which will work on more than just Valve-official hardware. The company says more demo videos will be released in the coming weeks.