OK, I've been playing this for a couple of hours, and I'm mostly commenting on UI things I've found annoying:

In planet admin view:

(1) something needs to be done to make it visually obvious what "type" of tile (e.g. arid/plains/etc) it is and if there are any special "other" bonuses, without having to mouse over it.  Suggestion: use another small icon (just like the "bonus" icons), and put it in the top of the hex.

(2) Can't replace existing structures - my initial placement put a structure on a bonus tile that I don't want there. Won't let me replace it with another structure. I have to destroy then build. In GC2, I could take advantage of "converting" the structure to save me some build time. I want that back.

(3) The Ship view takes up the whole screen, and it's pretty darned hard to make it go away. You have to click all round outside the box to get it to disappear.  Just delete the Ship Preview here. That's what the Ship Builder thing is for. I can gaze lovingly at the models over there; here it just make the UI less efficient.

(4) Clicking on a building "proposes" to place it in an available space. That's fine. But clicking around the interface to get it to stop with the "shadow" building placement is annoying. I should just be able to right click anywhere to stop placement of the current building type.

(5) it's unclear if bonuses on tile applicable only to improvements of the proper kind.  I.e. if the bonus has two categories: +2 Production, +2 Approval, and I build a factory on it, do I only get the Production bonus? Or do I get both?  What if I build an improvement that is neither?

Bugs:

(1) If you destroy a spaceport AFTER you'd put a spaceship in the build queue, The spaceship stays in the queue and WILL be built, even if there's no starport at the time the ship reaches the top of the build queue.

(2) seriously speed up ship moves in the main galaxy view. Less of the "graceful glide", just move the darned thing.  This reminds me of the move animations in Civ5, which is just *annoying*. We're playing a 4X here, not a RTS or FPS, and that's just useless eyecandy (in fact, more than useless, it actually detracts from the game because it slows down play significantly).

(3) On main screen - thermometer gauges for what's building under each planet, and the Research bar, need to have a "turns remaining" number showing.