Back in March, Microsoft announced that it would allow generic cross-platform play on its Xbox Live network. The move was essentially a public challenge for Sony to similarly open up the PlayStation Network, allowing for multiplayer matches involving more than one type of console for what would essentially be the first time.

Now, some major game developers are stressing that any technical hurdles to this cross-platform play have been overcome. Sony's walled-garden policy is the final obstacle to allowing play between Xbox and PlayStation systems, they say. "Right now, we're literally at the point where all we need is the go-ahead on the Sony side and we can, in less than a business day, turn [cross-platform play] on and have it up and working, no problem," Jeremy Dunham, vice president of Rocket League developer Psyonix told IGN in a recent interview. "It'd literally take a few hours to propagate throughout the whole world, so really we're just waiting on the permission to do so... It could be tomorrow, it could be longer than that. We just don't know—we're anxiously awaiting that, just like the rest of our fans."

Rocket League was one of the first games that announced cross-platform play between the Xbox One and Windows 10 (well before Microsoft's recent Play Anywhere initiative), so it's not that surprising that the title is ready to link in with the PS4 as well. But The Witcher maker CD Projekt says it's also simply awaiting Sony's go-ahead for a cross-platform version of the upcoming Gwent card game.

"We are keeping our fingers crossed for Rocket League paving the way," CD Projekt CEO Marcin Iwiński said in a statement issued to IGN. "Our upcoming Gwent: The Witcher Card Game will launch in closed beta for PC and Xbox One later this year, and Microsoft already confirmed Gwent's cross-play feature not only between Xbox One and PC, but also other consoles if they allow it. We also do have a technical solution in place for PS4 and would love to add Sony’s platform to cross-play at the start of open beta. All we need is a green light from Sony."

The new statements come on top of Blizzard saying last month on Twitter that it is "keep[ing] an eye on cross-platform possibilities on the consoles" for Overwatch, suggesting an openness to the concept should Sony allow it. At the same time, Blizzard has said that the game will never allow for direct competition between PC and console players, citing the relative advantages granted by keyboard-and-mouse controls.

In the past, Sony has allowed for games that enable shared online play between the PlayStation Network and the PC, but never for direct cross-platform play with its console competitors. Back in March, Sony told Gamespot that the company "would be happy to have the conversation with any publishers or developers who are interested in cross-platform play." So far, though, it seems like any such "conversations" with Psyonix and CD Projekt haven't really led anywhere concrete. Sony hasn't responded to a request for comment on this matter from Ars.

These kinds of public statements from developers are probably what Microsoft was hoping for when it made its public overture months ago. It's not a good look for Sony to be seen as the only obstacle to a gameplay feature that many players and now developers are publicly asking for. "I think that the more companies that show the world that they're interested in that sort of thing, and the more communities that get behind it, the more likely it is that it'll happen," Dunham told IGN. "We think that the gaming community as a whole is the final voice in this—it's what they want which will determine where we go eventually."

Getting Sony to open up would probably be a good thing for Microsoft, which has seen relatively slow sales for the Xbox One in comparison to the PlayStation 4. In a world with cross-platform play, though, the Xbox One might suddenly get a second look from potential buyers who want to play a new Halo in addition to playing Call of Duty and Madden with their critical mass of PS4-owning friends.

Even if Sony doesn't take the hint, though, the increased pressure from developers could have an impact on how those developers start thinking about their relationships with both console makers. As more and more developers come out in favor of letting players interact between platforms, Sony might find itself with the difficult choice of ignoring those developers or making a move that could benefit its console competition.