Anyone following the news of the Steam Machine device, specifically the Steam Controller, will undoubtedly know that the Valve team is still searching for the right combination for the controller to suit PC gamers on the device. Yesterday, the team unveiled the fourth experimental design of the controller, in which they have removed the directional buttons and replaced them with a joystick similar to those available on PlayStation and Xbox devices. Just as a reminder, the release of the device has been postponed until 2015, which indicates that we may see several experimental designs for the controller in the future. Best regards.
