My first impression about game 0.4.8 looks amazing and finished game but very complicated for beginners. I guess it would be nice to see few tweaks:
1) Better Single Player menu: simple recommended settings to start the game: "easy", "medium", "hard" and "custom". Every game difficulty should have score factor 100%-1000% and score table and Custom can automaticallly apply score factor based on settings.
2) Official starter guide with 5-10 guided turn or just similar video.
3) More default ships based on unlocked hulls / technologies researched. It would reduce clicks for new players and simplify gameplay. Other ship designed should be automatically hidded/obsolete when new better design avilable.
4) Easy accessing "seed" option, 0.4.8 has "random" text instead of actual map seed number and prevent replaying previously played map.
5) Roadmap has interactive space/ground battles - amazing idea!
6) Sometimes at end the game I unable to send troops to the ground or my ships deal no damage to the enemy ships. Which is very confusing. If it is related to the my low technology level it should be explained in the logs. (Your ships deal no damage and destroyed or similar). Or when I try to send troops to the ground due technology limitations it should show some sort of message to the user where "invasion" button showen / tooltip.
7) Ship fleets list should be accesced from the global menu, where currently only you can find statistics. So user can control all his fleets and route them.

9) touchpad two finger scroll (I guess mouse whell scroll) too sensitive it jump for 8-10 items when scrolled slightly and can be more smoothed.
10) Build menu can differ interstellar ships and planet only ships (Outpost Base, Colony Base, Trop Drop) marked as ships, which is a bit confusing for beginers. They may be called 'pod'
11) Concentration Camps should be prerequisites for: banks, jurisprudence, adversments, TV, copyright and intellectual property.
12) Technology tree should have additional simple view / blocks: basic research (Nascent AI), basic production (Fusion), laser ships, improved reasech (orbital generations, microgravity industry), impoved production (exorobots), plasma ships, advanced reserch (growts, trancendent design), advanced production, death rays fighters (titan hill etc). It is not optimal choices but helps a lot for new players and improved gampay on easy/mediul gameplay. Player still be able to removed unwanted research from the list.
13) Active stargates can be shown on map with dashed yellow line between planet. So it would be easy to find.
14) Missing end game dialog in single player mode, "You Won!". As I understand here is two win conditions, by war, or by since. [Quit] [Continue]
15) Planet Suitability the main feature in the game and should not be hidden as context menu. Better to have all time enabled / persistent button on planet overlay.
Overall: amazing game! Few bugs. AI very generous even on Manacal level, it could kill me in seconds, but did not hurt until its end. Maybe, having better AI for higher difficalties can be good idea.