Naev is a 2D space trading and combat game, taking inspiration from the Escape 
Velocity series, among others.

You pilot a space ship from a top-down perspective, and are more or less free 
to do what you want. As the genre name implies, you're able to trade and engage 
in combat at will. Beyond that, there's an ever-growing number of storyline 
missions, equipment, and ships; Even the galaxy itself grows larger with each 
release. For the literarily-inclined, there are large amounts of lore 
accompanying everything from planets to equipment.

The ndata download (included in the info file) is required to play.