Though it might be more fun played with one of these

There will be no game exclusives on SteamOS or the Steam Machines, according to Valve.

Despite some speculation that Valve could be using its upcoming OS and hardware to house some of its titles exclusively, the company has said it has no such plans.

"You won't see an exclusive killer app for SteamOS from us. We're not going to be doing that kind of thing," Valve's Greg Comer told IGN.

It's better to be free, man

The same goes for third-party titles as well, according to Valve's Anna Sweet.

"Whenever we talk to third-party partners, we encourage them to put their games in as many places as possible, including not on our platforms," she added.

"That would go against our whole philosophy, to launch something that's exclusive to SteamOS or Steam machines."

So there you go. As far as Valve's concerned right now, Half-Life 3 won't be a Steam-only launch. Well, there was no acknowledgement of the game actually existing, but it's ok Valve, we can read between the lines.