Giant Bomb PC Gaming Hub explained it best; "Space Diablo, but with consequences."
The game is an action RPG, that takes place within a 4x RTS Strategy game played by the AI. You are a mercenary in this galaxy, and your mission is to achieve victory in one of the following ways...
By achieveing a Military Victory, by being allied with the last surviving race and destroying all your enemies.
By achieveing a Diplomatic Victory, by uniting all surviving races in a single alliance.
By achieveing an Economic Victory, by accumulating wealth for the Drox Operatives.
By achieveing a Fear victory, by destroying all who stand in your way without mercy.
By achieveing a Legend Victory, by completing assignments and missions given to you by the various races and exploring the galaxy.
And finally by completing any and all assignments offered to you by your commanding officers in the Drox Operative's Guild.
To succeed in these goals, you must travel the cosmos and upgrade your ship as you gain experience and randomly generated loot.
Here's where the game get's interesting... As stated, there is a 4x RTS Strategy game being played by the AI all around you. You, as a Drox Operative, are able to influence the empires in the Galaxy. You can instigate wars and end wars, you can aid ships and colonies in distress, you can even fight in wars alongside an empire. Everything you do in the game influences the galaxy around you in some way.
The game is excellent, and highly enjoyable in my opinion. I highly reccomend it if you're looking for a good Sci-Fi RPG. The game is also multi-player, allowing players to work together or against one another, so that's another plus in my book. The game is $19.99 normally, and I've seen the winter sale drop it 50% for it and the expansion.