Sony is the only hold out for connecting its PS4 players to folks on other consoles. Dunham said that since Rocket League's launch, at least one person from his team has been in contact with PlayStation "every single day" since. The topic of cross-network multiplayer has come up several times, but the response rarely changes.

"There have been slight variations on how it's been presented to us, but essentially it's the same answer," he said. "It's 'not right now" or 'It's something we'll consider.' That's paraphrasing, but there hasn't been any movement."

In contrast, when Psyonix approached Nintendo about cross-network play, the studio had a positive response the same day. Microsoft took a bit longer.

"I think it was only about a month after our release, maybe less, that [Microsoft] said, 'Okay we're gonna go ahead and do it. You guys are gonna be the first [to have cross-network play].'"

Dunham said that once cross-network play is available for every game — not just his own — that games with shorter lifespans (think: the yearly turnover of CoD) will naturally reverse the attrition.

He gave the example of a family where one cousin could only afford a $299 Nintendo Switch and another had the $500 Xbox One X. Both will be able to play Rocket League and Minecraft together this fall despite being wildly different pieces of hardware and technology. "That means a lot to that family. Imagine how many friends and families that'd mean a lot to."

Warm sentiments aside, cross-network play makes a lot of sense for other reasons. Having access to more players would result in faster matchmaking, better matches and access to better opponents, according to Dunham. In fact, Sony has already allowed it for games that have a dismal player count. Early last year DC Universe Online (a PS4 launch title) opened up cross-platform play between PC, PlayStation 3 and PS4. Last autumn, Eve: Valkyrie for PlayStation VR could connect to players on both HTC Vive and Oculus Rift for online space dogfights. Knowing that the company can do it, Sony only looks stubborn for not playing nicely with competitor's consoles more broadly.

Seemingly in response to Sony's recent comments that cross-network play wouldn't be appropriate for players of all ages, Dunham said that his team already has safeguards in place.

You can't use voice to communicate via cross-platform, for instance. All you can do is use pre-written quick chat messages. If a Steam user has an off-color name, there's a filter in place to block it out. Essentially, you can't even tell if someone you're playing against is on a different piece of hardware than you.

"We have all these protections in place to ensure your experience isn't terrible," he said. "There's always gonna be trolls that can find a way to do anything, but that's not platform agnostic — that's universal."

Psyonix has tested cross-network play extensively in closed environments to make sure that Xbox-to-PlayStation play is actually possible, and Dunham said that it works seamlessly. It's just a matter of matching network protocols and requirements from the disparate systems.

"I don't view it as a competitive loss to allow cross-network play," he said. "I view it as a competitive disadvantage not to have it. Especially if you're the only one [holding out]." With Sony being the odd company out, if there's enough public demand for the feature hopefully the leading console seller will reconsider.

"I don't think anything is ever a done deal," Sony's Jim Ryan recently told Eurogamer. "Anybody who is dogmatic in that manner is typically a fool.

"That said, to my knowledge, there is no live conversation ongoing at the moment." So much for that idea, then.

Follow all the latest news from E3 2017 here!