What is Article 13?

Article 13 of the Proposal for a Directive of the European Parliament and of the Council on copyright in the Digital Single Market, is based around the relationship between copyright holders and online platforms, like itch.io, compelling the latter to enforce tighter regulation over protected content ("information society service providers that store and provide to the public access to large amounts of works or other subject-matter uploaded by their users shall, in cooperation with rightholders").

According to the Article, those platform providers have to “take measures to ensure the functioning of agreements concluded with rightsholders for the use of their works or other subject-matter or to prevent the availability on their services of works or other subject-matter identified by rightsholders through the cooperation with the service providers.”

How will you solve it?

Youtube has the same problem, but they are using an AI system to check the videos. this is not possible with a game with a lot of files. And "report abuse" it's no more ENOUGH.

Well first to understand is that EU users will be effective by this not US. The US has other laws that clash with article 13 but still yes i can see how this is confusing. If EU law is pass then itch.io can do two things:

1) Make a US version and EU version

US version stay the same while EU version is more with the laws of that land.

2) Still remind worldwide with a requirement

So we developers have been under a honor system to credit people in our game. If the law pass itch.io can add like a credit system like in newgrounds to offset the law. There is no way for a robot to look into a game credit so it would be the responsibility of the developer to credit or else no game will get lunch.

The report button is still a good system because copyright holders can ask itch.io to remove it. That is the system EU wants. If a credit system like newgrounds is added it is easier for copyright owners to spot people who stole it. This can also be used to track games that use copyright owner's name, itch.io can have a system where the name of the person request to not be on any game he did not upload or something then a bot can take it down faster.

The only problems it would face is people uploading copyright images/video/music under fake names. Still that is something all sites face even youtube.