Hey there,
I sure hope you don't mind horribly late feedback?

Sounds like you've focused on gameplay, concepts and playability so far, before adding in graphics and lots of eye candy - a valid approach, of course with the disadvantage that you have a lot of work until you can show something that doesn't trigger the usual responses. But well, all you need to do is ignore them from people who apparently did not read the post (and there's always some of those).
For multiplayer, be aware that some solutions that work fine in single player games are very, very difficult (if not impossible) to make work in multiplayer.

Given how much seems to be possible already, it's a bit of a shame that the screenshots convey only little of that. I know it's only placeholder artwork, but a video or something that better shows how it plays would be much appreciated! I'd ask to become one of your playtesters, but I don't have time these days, and I'm not a big fan of strategy games anyhow. Still, I'd like to see more.

On to the shots, then!
I don't really like the stars-effect. The smoke emittance doesn't work for stars. Their incredible size dictates that they're spherical, so your stars should in general also have a round silhouette. I realize that there's things that deviate from that shape, but those are much darker than the star itself, which is why we only see them a) when the main star is dark (eclipse), b) when the picture is overexposed - both aren't the case here. For cool inspiration and the chance to check it out for free, try Celestia (star shot from celestia). Note how the shape is spherical. The whole thing is also very bright - I don't think you should add dark spots, though a very slight structure in the star could work. In real life, there's something called Limb darkening, which makes the edges of stars appear darker, but for video games and the perceived reality there, a bright outline might work better. The effects in the last shot are cooler and better, but they still differentiate too much from the round shape IMHO.
I suppose you'll have to try there! And of course I realize this is all talking graphics, which I understand weren't the focus before. Sorry!

A problem with space strategy is the big distance between objects. Perhaps by adjusting camera.arc you can choose camera angles that allow you to convey the distance & depth and still have objects other than the selected one visible. This is a wild guess only, and may very well not work.

Whats that yellow ring around some of the planets? Given the GUI, I suppose it's the selected object? In that case, maybe you can add some 2D-elements (such as a box around the object) as well, that would work better for some camera angles -- or planets with their own ring structure.
I'm not a big fan of the GUI as it stands. The gradient does not convey "space" or "scifi" to me. Overy pronounced shapes and boxes with edges that stand out seem to be the standard. Try also some transparency effects and alpha channels to make it look even space-y. Last but not least, animating those makes the player automatically look to the corresponding GUI-element, so you can use that to direct their vision to where the important information is. Just make sure the animations aren't too long.

Let's talk skyboxes. Spacegames are empty, yes, and so is space, but in games, we can get away with unrealistic, unusually colorful space backgrounds. I refer here to every space game ever for inspiration - your current skybox looks a bit bland.

I like the idea of buildings on planets! Why not make them affect gameplay, if only a little bit? As long as its intuitive (say, a city increases population), it would differentiate planets more, which I think would be a good thing! The scale here is all wrong, and you'd have to decide NOW on whether or not to stick with that (and say it's symbolic only), or with only changing it on the planets texture, and in turn having it a bit more realistic.




Sooo, lots of criticism here. But don't take it personal - I wouldn't have taken the effort if I didn't like what I see. It seems you're on the right track with focusing on gameplay first, and I'd love to see more of that. Good job so far, keep going!