Is that 27" iMac screen just not cutting it for your gaming needs? Introduced today, the new Big Picture mode available in the Steam client for Mac offers a front-end for your games that's controller- and TV-friendly.
Big Picture mode can be easily navigated with a gamepad, offering access to the web, store, and community features without the need for a mouse. The mode also features larger fonts and interface elements designed to be viewed from a distance of 10 feet. Not all Mac games support gamepads, though, so for those cases you can still navigate and play using a mouse and keyboard.
The overall impact of Big Picture mode is actually quite similar to playing games on a dedicated consol