A few centuries ago a cataclysmic catastrophe nearly ripped your galaxy apart - since then unsurmountable hyperspace rifts have appeared throughout the galaxy and the center of the galaxy has been cut off from the rest. At the same time a mysterious alien species called "The Xsotan" has appeared in the center of the galaxy ...
Avorion is a sci-fi sandbox where players start out at the edge of the galaxy and must find their way to its core. Players build their own ships, which they will use to explore the galaxy, trade and fight.
Space ships are of large scale with crews, turrets and energy systems that players have to manage. The galaxy gets more hostile, but also more rewarding the closer players get to its core. You're free to play however you want, as a mercenary, freighter captain, admiral, scavenger or pirate, it's all up to you.
Avorion focuses more on fighting, exploring and actually flying around instead of building. Creating new space ships is easy and less micro intensive.