Some notes as I started playing:
Nice to go right into a pretty system view. I could use some guidance on what to do, what things are. Looks like a 4x game, so I'm going to try to harvest resources, ugprade structures, build ships. Not in the mood to read help files atm.

I clicked into my planet. The structures need tooltips (use the title attribute) to show names. When I had one building, the layout got funny, I think the countdown timer is messing up the page layout but didn't look into it. Looks like I can't queue any buildings, boooooo. You should at least make it a premium feature. And if it already is a premium feature, say so, not "construction facilities busy".
Ah, resources are per-colony. I was wondering why I didn't spot them at the top of the page. Give tooltips to the icons, I have no idea what they are.
On to research. I like
tech trees, and on a lot of games you're wasting nonrenewable time by not having something actively in research. The icons for Core Research, Quantum Storage, Engine Development, and Construction Methods didn't load, I have a white square for the first and light gray square for the rest. You know, I bet it'd look really nice to put a CSS border radius on the bottom corners of the boxes that say "Lvl 0". Clicking around, I can't afford anything, no fun. I wanted to see how it worked.
Nice map, the overview and system view are both pretty. I can't guess what the lines are for.
Shipyard. Apostrophes on a noun indicate possession, you don't need them for plural. Whatever's between Cargo and Expedition is missing a title. Don't have the research or resources to build anything, so not really anything to see here. This might a good place for a help tip that I need to go research things, you can't give too many links.

Hit "My Planets" to try to find my colony again and go look at upgrading any mining/research buildings so I can start doing things, but I've lost it. The green "use the form" really doesn't fit into the page. I have one colony, why isn't there a link? I don't even know what its name is to search for it. Hit search on empty form, glad that worked, but I can't click the colony title to go to it, and the planet icon actually takes me to the system rather than the colony. And on the map, I can't click the planet to go to it. And I can't try to click the green square for the colony because two planet tooltips are covering it and don't go away. Uhm.
OK, found it. Weird that these buildings have "lvl 0" on the picture, but research has "lvl 0" underneath.
Can't afford anything, don't see anything else to do and I don't want to do the mental math to figure out how long I have to wait for resources to do things, so I'm just closing the tab.
It looks like you've got a great game started. It's attractive, looks complex, and seems to work well. But if I wasn't really familiar with 4x games, I'd have been pretty lost on what to do. Consider a little quest system to prompt the user to build and upgrade their first mines, start research, build a ship. I start the game really limited in what I can do, so I don't feel a lot of reason to make sure I return. I don't feel like I did much, and I have no idea how long it'll be until I can actually start sending ships out.
Set up a cron job to mail new players who've gone inactive, I bet there's a ton of them who need a prompt or two to remember to play the new game. Because I don't have anything telling me it'd be good to return at 6 PM to build more stuff, it's just not on my mental calendar at all.