"Coming first" is succinct, honest and to the point. No ambiguity and one I personally like a lot. I know right away that if I want to play it soonest, I need this device. If not, I must wait. Easy.
"Only for"/"Exclusive" is fine too - it doesn't matter if "X: Expanded Edition" then goes to another format since that's a different SKU then.
"Designed for" on one hand, duh, obviously. But then comes the ambiguity of in what way is it designed for X, like what, faster load times? What does this phrase try to say, exactly. I've seen legal teams be more picky on the dumbest of shit, so allowing this is a bit puzzling, personally.
Phrasing around which platform is the lead in terms of development is neither catchy nor that great a marketing message, so I can see why they would save such info for Press statements and QAs instead.
Just my take on it.
Or we continue to get such awesome phrasing as "the experience Xdevice is a game changer" or something about "experience".