SpaceForce: Rogue Universe
Spaceforce Rogue Universe is a story-based or open -- depending on your choice of play -- space sim with a focus on missions, combat, trade and epxloration, all taking place in a large and expansive universe.
Concept
If you choose the story mode, you'll play the son of a slain fighter pilot looking for his lost sister. If you play the open mode, it's all up to you, as you can trade, accept missions and so on.