As for the Spain-Ghana match, Spain got dominated for large spells yet again. It is safe to say this team isn't nearly as talented as the U21 team. The biggest difference is in midfield. Oliver Torres may grow up to be a cracking attacking midfielder, but he is not the dominant type. I think Campana, the captain, was supposed to be one, but he has been one of the weaker Spanish players so far.
Overall, tournament is reminding us that this is U20. So many erratic plays, unforced errors. From Barca's point of view, Delufeu seems a very fast, tricky winger on the positive side, but also a bit of a primadonna walking about the pitch quite often demanding the ball. The main worry is that he has a bit of Tello in him. Wrong decisions, some simple errors when passing 4-5 yards and just looking erratic.
He's still a teenager, he may iron that out. But in my experience of watching youth tourneys, players like Thiago, Iniesta, Isco, Canales stood out even at this level with a bright head. Torres was erratic though, but managed to become of the better strikers in the world football for a while.