Here's something that's causing a bit of controversy with the gamers of the world: apparently, Microsoft isn't interested in allowing PEGI 18-rated games on the Windows 8 App Store. In Microsoft's list of Windows 8 Marketplace certification requirements, the company says, "Apps with a rating over PEGI 16, ESRB MATURE, or that contain content that would warrant such a rating, are not allowed." This is part of the requirement that Windows Marketplace apps must be "appropriate for a global audience."
Earlier in the day, that caused a bit of confusion among some people. At first, it may sound like Microsoft doesn't want M-rated games on the Windows 8 Store, but in a statement to Forbes, the ESRB says that Microsoft will actually allow M-rated games on the app store - it's Adults Only-rated games it doesn't want popping up on there. That's understandable, considering that most retailers won't even carry AO-rated games, and Microsoft, Sony, and Nintendo don't want AO games made for their consoles.
So why then is Microsoft saying that PEGI 18 games aren't allowed on the Windows 8 Marketplace? The PEGI 18 rating is essentially Europe's equivalent of the ESRB's M-rating, so it's a bit odd that Microsoft doesn't want PEGI 18 games on the Windows Store but it's okay with M-rated games being sold through it. With this rule, PEGI 18-rated games like Mass Effect 3, Skyrim, and Modern Warfare 3 won't be allowed on the Windows 8 Marketplace, but their M-rated US counterparts would be.
At least, that's the assumption from a literal reading of the rule. It's important to point out that Microsoft isn't banning PEGI 18-rated games from Windows 8 machines, just the Windows 8 Marketplace, so players would still be able to purchase and install them from places like Steam and GamersGate. Keep it tuned to SlashGear, as we'll update you if Microsoft offers some kind of clarification to this rather confusing certification requirement.