As a casual gamer I think you'll enjoy the customization of the game. Being able to choose your player portrait, faction logo, naming your ships and planets, outfitting your capital ships with special abilities, building your ideal fleet composition, choosing who you want to ally with, trade with, and complete missions for, who you want to place bounty on, designing your own map, etc 
(edit) I forgot to mention, if you are not the competitive type, you may also enjoy teaming up with a friend to take out the AI. In the latest build they are a real challenge. You may like to start the AI on 'easy defensive' then as you improve your skills move him up to 'hard aggressive'.