The space phase is really draining the hours. It just feels like there's so much to do and so much to see. In a way, it reminds me of the of the planet-hopping in Mass Effect only better in every single way. It takes a while to unlock all of the tools, but once you start to get things unlocked the game really gets fun. I've spent hours just roaming from star system to star system terraforming planets and plopping down colonies. Also, I had to school some upstart empire that thought it could bully me around. Oh they wanted peace in the end, but I wasn't in the mood to give it to them.
On the other hand, it sucks that you have to constantly babysit your colonies. Your fleet much be the only one in your empire because every time some pirates nose around they scream and cry for you to do something about it and it's really, really annoying.
