There were a lot of things that were good about EVE (it's been about 4 years since I played).
Examples would be:
The Economy.
Ship Configuration System.
The Artstyle.
The security model.
The unforgivingness (made you think carefully before you acted).
The problem was just that the combat always felt a bit bland and favored players with the biggest ISK supply and XP. So in reality you needed to be part of a huge corp and wait for months for skill training to be competitive.
I hope this is the opposite of EVE in practically every way... except the high-level concept. Let's not give Notch any ideas.