That was a very good introductory episode. It gave us a decent grasp of the political climate and the world's current situation. I enjoyed the show's pragmatic approach to war. I'm sure you can poke holes in the Demon King's theory, but it seems believable enough within the context of the series. Through war, the world has reached a precarious equilibrium that is threatened to be destroyed by peace if certain measures are not taken. Works for me. The bouncing boobs made the Demon King's argument even more convincing.
Not sure what the meat of the series will be yet (other than the DK's boobs): the romance, the comedy or the politics? I think I would enjoy a mix of those elements best. The best bit of comedy in the first ep was the removable horns. It hadn't even occurred to me that they might be fake, so the gag worked perfectly on me
I liked the art direction of the show, particularly the background art. The scenery is very pleasing to the eyes. I like the "painting effect" (not sure what to call it) they're using, the only problem is that the characters are animated normally so it's a bit jarring.