A story line that explains the origins of your particular species. I personally would like to see for the Humans, a story that would at least loosely incorporate mankinds myths and legends. I think it would be pretty interesting if there were a essentially a quest line that if you follow on it, you will receive certain bonuses as well as uncover the true origin of your species. I acknowledge that creating specific origin stories and all the anomalies and techs that could come with it, for every single race is a lot to ask. I think that maybe the prescripted species ought to have a quest line and for any custom species there should be one of a random set of quest lines. I think that it would add a fun, immersive aspect to the game that would bring you even closer to your particular empire, you know, it's always easier to fall in love with a character if you know their back story, where they come from. Besides that, I would like a Cosmetic DLC for Humans that further still, make Humanity addictive and interesting to play as. These are just thoughts, I personally think that they would make a fine addition to what I have seen so far of a game that seems to have infinite potential.