Just a few things I found unintuitive or confusing, and suggestions to improve.
1. Trading items: Move the "trade items" button to the equipment screen. It's more intuitive to go from there than from the unit actions screen.
2. Resource building: If building on resources uses the city's queue, it should be choose-able from the main improvements menu. If it is done parallel to the main city queue, there should be a countdown indicator showing turns left until completion, instead of just the mouse-over.
3. Lack of variety: I am confident this will be addressed as user-made and official maps are released.
4. Lack of custom faction creator; Although I understand Stardock's stand in this matter, I believe that a custom faction creator for single-player play would be preferable: As it is, I'm expecting that's going to be one of the first support apps a modder creates.
5. Governors: These were one of the best things in later GalCivII. I'm looking forward to seeing them in Elemental too.
Overall verdict: One of the things I love about Stardock games is that I always feel like I'm in an open beta: the game changes and improves over time based on feedback. I'm confident Stardock will smooth out these issues over the next few weeks and months. As it is, I played well past my bedtime last night, even with these issues: "One More Turn Won't Hurt-itis" is back with a vengeance.