'Seed' was pretty interesting and didn't require fighting to gain levels... But that was also reliant on what you chose to be - Engineer, Scientist and so forth.
I'd like to see a 'Space Opera RPG' sort of like Star Trek that uses multiple engines.
I'm not entirely certain why developers haven't looked at this type of thing... What I'm getting at is a game where you cane conceivably freely fly your spacesh…