To challenge a platform synonymous with PC gaming, the Epic Store needs its own games. That's what I said last year , and I think it remains true, but for crying out loud, Epic, stealing Metro Exodus from Steam 18 days before launch? Maybe take a sip of water and finish what's on your plate—like, say, adding cloud saves—before going back to the buffet. What a coup.

I figured Epic would start 2019 slowly, focused on playing feature catch-up with Steam, adding library sorting tools or community hubs, which it still lacks. After revealing Satisfactory, Maneater, Journey, Hades and others as exclusives last year, I didn't expect it to throw even more Fortnite V-bucks at the problem of taking on Steam. At least not so soon, and without adding new features.

What Epic and Steam do now will change the games of our future.

But not even a full month into 2019, Epic did just that, and it's hitting so hard that Valve has actually responded for the first time. It's bizarre to see Valve on the defensive: the architect of modern PC game distribution makes declarations , not appeals. But this clearly stung. Not only did 4A Games and Deep Silver unexpectedly pull Metro Exodus from Steam—the platform both have succeeded on for years—they announced this defection on the Steam store itself. Imagine if Metro had occupied shelf space at GameStop for six months, then announced at the last minute, visibly on that same shelf, you could only buy the game at Target. Yikes.

Deep Silver and 4A used Steam like a storefront window display and then split.

Valve rarely responds to insults (I know, because I insult Valve all the time and they never want to talk to me), but for once it's licking its wounds publicly:

"We think the decision to remove the game is unfair to Steam customers, especially after a long pre-sale period," Valve wrote on the Metro Exodus store page. "We apologize to Steam customers that were expecting it to be available for sale through the February 15th release date, but we were only recently informed of the decision and given limited time to let everyone know."

War isn't fair, and as of today, Epic has properly declared it. Valve's response is pouty in comparison, a reflection of how secure Valve's walls have been until this point. It lost EA to Origin, Call of Duty to Battle.net, and now Bethesda has its own platform, but publishers defecting to first-party launchers was emigration—losses, minor rivals, but not an assault on its heartland. Epic is different: it's taking big third-party games, including The Division 2 . It's putting holes in the fortress, where GOG and itch.io have only grazed it with anti-DRM discourse. Worse, Metro is cheaper on the Epic Store than on Steam, at least in the US. Brutal.

Metro is front and center on the Epic Store, naturally.

No one has ever done this

In part by being the biggest, Valve has bagged a lot of customer loyalty, but developer and publisher loyalty is for the first time being seriously called into question. Deep Silver and 4A used Steam like a storefront window display and then split. That's cold, but Valve isn't faultless: its 30 percent on-store cut, surprise announcements, and 'anything goes' Steam Direct policy have seemingly fostered the perception that Steam is a utility—a thing to be used however is convenient. What relationship Deep Silver has with Valve I don't know exactly, but the bond wasn't stronger than Epic's offer. (To be fair, we don't know how much money Epic is throwing at these exclusives, and we hope to find that out to determine just how much a defection costs.)

Right now, all it means for us is a few more decisions: whether or not we enter our credit card information into another launcher, whether we play Metro Exodus this year or next. In the long term, though, we may remember 2019 as a turning point for PC gaming.

Over a decade ago, Steam's digital distribution and auto-updating changed what was possible for games—and in doing so, it changed the kinds of games that were being made. Fast forward: DLC, microtransactions, Steamworks, Early Access, Steam Workshop, Steam Greenlight, Steam Direct, discoverability algorithms, wish lists, curators, and everything else that Steam was and is played a part in determining what we're playing today. Would there be a PC version of the Resident Evil 2 remake had Steam not been Steam? Would Euro Truck Simulator exist? We can't test the butterfly effect without a time machine, but it's no stretch to say that platforms matter. Even outside of Steam and away from the PC, the Xbox Live Arcade affected PC gaming by pushing certain indies into the mainstream spotlight. It's fitting that Super Meat Boy Forever, the sequel to one of those games, is an Epic Store exclusive.

Maybe it's more surprising that it took this long for Steam's nemesis to emerge.

What Epic and Steam do now—beyond crying 'no fair!'—will change the games of our future. As one consequence of Epic's onslaught so far, it teamed up with Improbable to put $25 million into transitioning SpatialOS games away from Unity, which can't mean nothing.

Although we bemoan some of the inconveniences of corporate giants fighting over the games we play, PC gaming has always been in a state of fragmentation and competitive flux. Maybe it's more surprising that it took this long for Steam's nemesis to emerge. In another timeline, it might've been Riot Games or Blizzard or CD Projekt—and it'd be wrong to count out any of those companies, even as Valve and Epic dominate the ring today.

At the moment, inconvenience is all this means for us. Steam isn't going down because of Metro Exodus or The Division 2. But there'll be ripples—no one has done this before!—and anything we thought was certain about the next five or so years in PC gaming is far hazier than it was yesterday. Steam changed everything once, and it feels a lot like we're on the verge of another metamorphosis.