Best space 4x Grand Strategy there is atm. Pricy, but worth it. I consider myself no fanboy, I just find this game to come closest to my idea of a great game in its genre.

Up to 1400 stars, each with its own planetary system (they orbit their star! moons too! ). Plenty of resources to secure, gather and a few to kill for.
Sprite graphics but this allows for easy modding (modding is a thing, new races, total overhauls = star trek, star wars, mass effect, etc) and huge fleet battles (easily hundreds+). Steep learning curve but manageable and automation allows you to learn at your own pace or if you just don't like some parts of the game, leave it to the AI (taxes? research? intelligence? ship design?).

Plenty of characters that help in various fields, all with skills that improve with use and traits, both positive and negative. No one likes that Scientist that increases enemy Steal research operation chance by 200% right? Or this dumb Fleet admiral that deceases the skill of any other character present in the same place. Not only scientists and fleet admirals but also ship captains, troop generals, colony governors, intelligence agents, leaders or ambassadors.

You are also able to pick your government type from Monarchy, Republic, Democracy through Technocracy and Hive Mind up to the legendary Way of the Ancients. 12 in total, each with different bonuses/maluses to research speed, upkeep costs, corruption level and many more stats.
Don't like playing an empire? Fine, go and play a pirate instead! With kinda asymmetrical gameplay go and pillage and raid planets, smuggle some goods, built an army for hire, search the galaxy for secrets and sell those to the highest bidder. Or just be a pain in the #$@ and hit everyone and everywhere while playing cat and mouse!

AI is competent and might gang up on you if if feels like it and/or you give it a reason. Races have traits, dependable and friendly race will be your long-time ally if you work on it, agressive and intelligent might be your nightmare. AI controlled private sector (it earns money, you tax those money and protect it to earn more so you can tax more.. ) is the most unique feature, nothing like that is present in any similar game. Thanks to this the universe feels very much allive with hundreds of small or large private frighters flying around, doing their business (trade resources, carry materials from mining stations to your Space Ports so you can build that new shiny Carrier for your main fleet), which you can not directly control, but only indirectly influence.

For those concerned about DRM, know that other than install/update, the game can be played without Steam client running. This should help those that do not want / can not run it sometimes.

Overall, this game might be a refreshing suprise for those starved for a good space 4x / grand strategy, of which we had very few in the last years, and almost none good enough to last.