The UI really could use a lot of polish- it's exceedingly unforgiving, and the manual is pretty bad at showing startup. I also found what appeared to be a bug.
I jumped into a campaign, and here's a few of the first things I ran into.
1. Got control of my units, went to go found a city. Looked up the hotkey for founding a city in the manual, used hotkey repeatedly in several locations, nothing happened. No city was founded, no message was displayed. Eventually, after wasting several turns wandering around attempting to found cities in different areas, I explored over to an area where there was a 3rd unit, and after talking to that fellow, the game allowed me to found a city. What's up with the lack of feedback?
2. After founding my initial city, I notice that there's a spider lurking nearby. I stack together a few units, and go attack it, and win, though I lost a few units. I notice there's a second (much smaller) spider wandering nearby. I attempt to go fight it, but the game won't let me. Once again, NO FEEDBACK. It won't tell me why I cannot engage it in combat.
3. I attempt to engage "autoexplore" for a unit. Nothing happens. No feedback. I fiddle around with another unit, same result.
4. I save the game, exit, and go back in. The "Load" button is greyed out. I panic. Where did my save games go?? After several exits, looking around on my hard drive and determining that there were in fact, save games on my hard drive, I go back into the game. Eventually I find that campaign save games only show up after clicking "Campaign" again.
5. Back into the game. I finally figure out that I'm unable to fight the enemies because I haven't equipped a weapon. Auto explore now works, but I have no idea why it wouldnt work previously.
Other things which are missing critical UI information:
1. So far as I can tell, there's no way to tell how far a unit has already moved. There's also no way to see how far a unit CAN move before it will be out of movement. AoW: SM handled this by having you click two times- once to show you a path, and it would show you how far you could move with a "trail" the first time you clicked, and the second time you clicked, the unit would actually move. Not being able to tell how far a unit has already moved is a pretty amazing oversight.
2. There's VERY little feedback about when a turn ends. The only indicator is a tiny turn indicator at the top right of the screen. There is no confirmation dialog- seeing as both "spacebar" and "enter" will end a turn, it seems you could easily hit one by accident, and there should be more of an indicator when a new turn starts.
I have really high hopes for this, I hope that we see some serious UI updates in the early patches. The "ease of use" on Elemental leaves a TON to be desired so far.