Hope explained that while Valve’s controller is obviously designed to work natively with SteamOS, it can also be detected as a traditional controller by a PC running Steam but would have extremely limited functionality. “Steam constantly updates the firmware that is running in this device,” he said. “Even game by game, and eventually moment by moment, it’s going to be updating the code that’s running in the firmware. For that reason and a few other reasons, like updating configs and so forth, Steam is a required component wherever it runs, PC or Mac. Without Steam, if you plug this into one of those devices and run some game that’s not part of Steam, you would only get the most basic functionality. It wouldn’t actually be very valuable as a controlling device.”
“It would basically be a mouse with 16 buttons,” Coomer added.
Valve will also allow users to adjust things like sensitivity, which can be adjusted on a per-game basis in SteamOS. “On SteamOS, sensitivity is really easy to solve, because we can just change what the operating system’s sensitivity is on the fly, based on what you’re doing in a game,” Hope said. However, in Legacy mode or in Windows, sensitivity won’t be able to be adjusted. “Windows has its own sensitivity settings for input. The game has its own sensitivity settings, and our controller has its own sensitivity settings. We have to find this sweet spot where we’re averaging all three inputs into this spectrum,” he said. “It’s mostly solvable. There hasn’t been any game on Windows that we haven’t been able to play. But it takes a little bit more tweaking.”
So far, Valve has been able to successfully play (and win) games in every genre -- except for one.
“Somewhat ironically, our flagship at the moment that we spend a lot of time thinking about is Dota 2,” Coomer said. “You can definitely play Dota 2 with this controller, but we wouldn’t say to anybody who’s a serious DOTA player that this is an acceptable replacement for a mouse and keyboard for that game.”
“We have an internal joke. You can play Dota with the controller; you just can’t win,” Hope laughed. “Unless you’re playing against everybody else who has a controller, and then it’s a tractable problem.”
http://www.ign.com/articles/2013/11/04/how-valve-engineered-the-perfect-controller?page=1
Para que funcione al 100%, SteamOS.