Windows 8 hasn’t been released yet, but Microsoft’s upcoming software has already become a cause of concern for some figures in the PC industry, namely those in the computer-gaming space.

“Minecraft” creator Markus Persson has once again criticized the forthcoming operating system.

“Got an email from Microsoft want to help ‘certify’ Minecraft for Windows 8. I told them to stop trying to ruin the PC as an open platform,” Persson posted to Twitter on Thursday. The post had been re-tweeted more than three thousand times as of Thursday afternoon.

This isn’t the first time Persson, also known as “Notch,” has voiced his opinion on Windows 8 to the Web. In early August, the creator of what has become the poster child of indie video games slammed the operating system when chatting with the Reddit community.

“If Microsoft decides to lock down on Windows 8, it would be very, very bad for indie games and competition in general,” Persson said. “If we can keep open platforms around, there’s going to be a lot of very interesting games in ten years, mixed in with the huge AAA games that we all love.”

Persson also added that he would “rather have Minecraft not run on Windows 8 at all than to play along.”

“Maybe we can convince a few people not to switch to Windows 8 that way,” he said according to CVG.

Valve co-founder Gabe Newell was the first to speak out against Microsoft’s next operating system when he called Windows 8 “a catastrophe” back in July.

“I think Windows 8 is a catastrophe for everyone in the PC gaming space,” he said at Seattle’s Casual Connect. “I think we’ll lose some of the top-tier PC/OEMs, who will exit the market. I think margins will be destroyed for a bunch of people. If that’s true, then it will be good to have alternatives to hedge against that eventuality.”

This comment ignited a wave of criticism throughout the PC gaming industry, with Blizzard Entertainment’s Rob Pardo echoing Newell’s statement soon after. Pardo tweeted that he agreed with the Valve chief, saying that the release of Windows 8 isn’t “awesome for Blizzard either.”

However, the company recently confirmed “World of Warcraft: Mists of Pandaria” will be available for the platform, and a software engineer said that Blizzard has no “fear” of Windows 8.

“We put our games on platforms our players are already on, so yeah, it will be available on Windows 8,” Williams told CVG this week. “I think that we’ll go with the platforms that the most people re on. There’s no particular fear we have of Windows 8.”

The concern that Pardo and Persson share with Newell stems from changes within Windows that could compromise the platform’s openness. One such addition is the Windows Store, which essentially acts as Microsoft’s answer to Apple’s App Store. This means that any application which supports the new Windows 8 interface will have to be installed through this store.

Newell’s issue with this policy is that some PC makers could be forced out of the market due to dwindling sales margins, since these companies would depend on revenue from bundled apps or their own Metro-enabled apps. Microsoft would take a much larger cut of this revenue from apps with the implementation of a Windows Store.

Valve, in turn, is beginning to test an internal beta for its gaming platform Steam on Linux that will kick off next week.

Windows 8 will be available next month on Oct. 26, and Microsoft is holding a press event to introduce users to the final product a day earlier.