Starmaker: So yeah, it was an area as gray as "manufacturing copies" last century and it was further, ahem,
desaturated this century. You're breaking a license agreement, you think the license agreement is illegal and you don't have to follow it, yarr matey.
The European court just clarified, that the first-sale doctrine also applies to digital distribution, which wasn't a thing in 1908. Beside that the first-sale doctrine is quite simple:
As IP holder once you sold and transferred a legal copy for the first time, your control over THAT copy is completely gone. Just as with any other physical good. Any further restrictions on IP are applied by general copyright law, which doesn't specifiy any region restrictions (such laws would be a violation of WTO regulations).
You're breaking a license agreement
Actually, by buying games as a consumer I do not even have any "license agreements" (you know, what "agree" means?). And this is not changed by made-up "by doing this or that, you agree to this or that" statements written somewhere, because that's not how contract law works.
Either I agree to a contract explictly by submitting a statement of intention to the other party, or there is no agreement at all. And an agreement isn't required for just using a game or reselling it, as long as the copy was acquired legally (we're not talking about counterfeits here.)
On top of that as a consumer I'm protected by EU consumer law, which doesn't even allow me to agree to unfair conditions, usually found in US "EULA" documents. So even if I pretend doing it, these unfair conditions are automatically void with EU jurisdiction.