I played it through last night, couldn't even finish the game. I don't know how many turns the demo is limited to, but it's pretty low.
All I was able to figure out was the auto-explore and populating a new planet and setting up the buildings.
Negotiations were pretty tame with the AI civs, and I didn't figure out how to produce any troops.
I did try to produce another colony ship, but for some reason I was unable to land on any other planets with it.
The demo is confusing and buggy (it crashed on me a couple of times). If Stardock wants to sell this game based on the merits of the demo, then I'd say they need to consider doing some more work.