Earlier this week, Epic Games CEO Tim Sweeney had some rather harsh things to say about Microsoft’s Universal Windows Platform. The harshest of all was when he said that the UWP, “can, should, must, and will die.” It appears that Sweeney believes that the UWP is something that is actually a kind of move against the entire PC gaming industry in particular. He also wants the company to open the platform up for all developers and it’s this comment that seemed to spur Microsoft’s Phil Spencer to action.

The Xbox One chief posted his response on Twitter saying, “Windows has always been an open ecosystem welcoming the contributions of hardware and software partners, and will always continue to be. UWP is a fully open ecosystem, available to every developer, and can be supported by any store. Broad range of tools. We will discuss our next steps with the Universal Windows Platform at //build later this month.”

When Spencer was asked specifically how he felt about the comments Sweeney made, he seemed to be looking to be reconciliatory. He started the response by saying that Tim Sweeney is a friend and “he pushes for what he believes. I agree UWP has to be open and that’s what we are doing.”

However, since then, Sweeney ‘s overall fears and concerns have seemingly been based off of incomplete information. Firstly, Sweeney admitted on a podcast with Polygon that there’s no proof that Microsoft has an evil plan of sorts with UWP. “Microsoft is a black box. I know a lot of people there who are really awesome, smart people who want to do the right thing, but then there are other people there who appear not to be because some of the bad decisions they’re making on Windows 10. There is not proof of an evil plan to do this, but just the fear.”

It was on Twitter where the responses started coming in. When told that Windows 10 has been able to side-load apps since November 2015, Sweeney said, “Yes, am using Windows 10. Will need a couple days to document the win32 vs UWP develop/deploy/install differences in openness.”

Which is kind of weird when you consider his fears about Win32 applications being left out to dry while also stating that he needed time to really analyze the differences between the openness Win32 and UWP.

Furthermore, Sweeney said that he and Microsoft had been speaking privately about UWP for 18 months prior to this…and yet he liked Xbox boss Phil Spencer’s response on the openness of UWP. “I like the sound of this, and look forward to thorough technical details on UWP’s planned openness at //build.”

Something doesn’t quite fit in the midst of all this. What are your thoughts on Sweeney’s views? Let us know in the comments.

Note: GamingBolt’s Oliver VanderVoot also contributed to this article.

Epic Games and Microsoft go way back- Epic was responsible for consulting with Microsoft on the game design of the Xbox 360 (which is one of the reasons the system’s architecture turned out so developer friendly- they basically ensured Microsoft would add enough RAM to the system, for instance), and they also gave Microsoft one of their biggest hits in the Gears of War series.

Things have seem decidedly less friendly between the two of them of late, though- for instance, Epic seem to no longer be working with Microsoft on any game project. In fact, their newest game, Paragon, will be exclusive to PS4 on consoles. And today, Epic Games’ CEO Tim Sweeney has spoken out in a scathing indictment of Microsoft, and their UWP platform for Windows, which Microsoft is trying to spread using their PC gaming initiatives.

“In my view, this is the most aggressive move Microsoft has ever made,” Sweeney said in an open blog he published on The Guardian. “While the company has been convicted of violating antitrust law in the past, its wrongful actions were limited to fights with specific competitors and contracts with certain PC manufacturers.

“This isn’t like that. Here, Microsoft is moving against the entire PC industry – including consumers (and gamers in particular), software developers such as Epic Games, publishers like EA and Activision, and distributors like Valve and Good Old Games.

“Microsoft has launched new PC Windows features exclusively in UWP, and is effectively telling developers you can use these Windows features only if you submit to the control of our locked-down UWP ecosystem. They’re curtailing users’ freedom to install full-featured PC software, and subverting the rights of developers and publishers to maintain a direct relationship with their customers.”

Sweeney clarifies that he has no problems with the idea of a Microsoft curated storefront at all- it’s with how Microsoft are exploiting their position as the dominant OS vendor to push the store.

“I’m not questioning the idea of a Windows Store,” he said. “I believe Microsoft has every right to operate a PC app store, and to curate it how they choose. This contrasts with the position the government took in its anti-trust prosecution, that Microsoft’s free bundling of Internet Explorer with Windows was anti-competitive.

“My view is that bundling is a valuable practice that benefits users, and my criticism is limited to Microsoft structuring its operating system to advantage its own store while unfairly disadvantaging competing app stores, as well as developers and publishers who distribute games directly to their customers.

“The specific problem here is that Microsoft’s shiny new “Universal Windows Platform” is locked down, and by default it’s impossible to download UWP apps from the websites of publishers and developers, to install them, update them, and conduct commerce in them outside of the Windows Store.”

The problem here is, Microsoft’s UWP initiative is rather progressive, and a good step towards the future of computing overall- however, Sweeney is right in being as critical as he is of it, because of Microsoft locking it down the way they have. Sweeney thinks that an open platform, much like the legacy Win32 environment that Microsoft is trying to phase out with UWP, is the way forward still.

“If UWP is to gain the support of major PC game and application developers, it must be as open a platform as today’s predominant win32 API, which is used by all major PC games and applications,” he said.

It’s a remarkably frank and critical view of one of Microsoft’s biggest current initiatives- it is a lot like Gabe Newell’s warning against Microsoft from a few years ago. However, it is also justified. Microsoft have the right idea with UWP- but they need to open things up, instead of locking them down, if they want their efforts to gain any traction.