Well, if you come from AI War the most important aspect to know is, you are not directly in charge of a faction (like in AI War where you are the human commander), instead you are a solo person that tries to unite all the other factions. It's a really deep diplomatic game and less about "I will conquer them all!".
There are battles going on but you will only play a single ship against a lot of other ships (similiar to champion ships). You have not the power to eridicate races and have to depend on other races if you want to wipe of another race.
The core of the game is to interact with the "leaders" of the different races in a different way. The different races have entirely different political and social systems that directs the way how you can interact with them. The Burlusts for an example don't cara what you do for them, they are only interested in battles and will only listen to you if you fight (and kill) their leaders. Peltians however are communistic oriented and they have special voting proxies as political currency, you can literally buy everything in political meetings as long as you have the right amount of proxies.
A big part if the game is to learn how the different races work and what they want in order to make them do what you want.
You have to keep a balance between the different races, keep them in the right mood, create diplomatic connections between them and so on. In the end you will try to create a federation with as many races as possible but to manage this the races have to like each other and they have to like you as well or they won't listen to your idea.
It comes all down to relationships in the end.
If you have some problems with grinding, the game might not be for you. Some social relationships or stats will take a lot of effort to increase.
The tutorials are not very well made. You get BIG text walls and have to read them carefully or you won't understand most of it. There are dozens of stats that might confuse you, especially planetary stats and those get never fully explained ingame. Ont he other hand, most stuff isn't really THAT important, you will solely focus on the relationships and that's only what you need for the victory condition.
Battles might be a little too repetive after soem time. It's everytime you in a semi-turn based bombat system against a lot of other ships and you have to dodge the shoots while shooting down specific targets or managing other goals. You can auto-resolve battles however and in the end-game this is more comfortable because the auto-resolve funtion achieves victory a lot faster than you would.
If you purchase the expansion, there are two other modes, Betrayal and Invasion. Betrayal functions like traditional strategy games, hoard resources, build a fleet, defeat your opponents, conquer everything. It still has all that diplomatic stuff and you can go the sneaky way and backstab them all after pretending to be a friend but I found it more entertaining to rush down all combat researches and become an unstoppable behemoth that swallowed everything in it's way.
Invasion mode works again more like the classic mode, you have no power on your own and have to depend on other races but with the difference that this time you have to defend against a new threat that attacks in waves similiar to a tower defense game. The goal is to wipe that specific race and you have to convince teh other races that they have to put them down before it's too late.
What me amazes everytime is the big differences between the races. No race is like the other, some may have some common traits but thes still have their own systems and while it works well for that race YOU are the one who have to deal with all the systems together in order to reach your goal. A lot of the fights between the races comes from the different ideals of each one. The Acutians are interested in money and everything is okay to do as long they get enough profit from it, even blowing up an entire planet.
Thoraxian are your typical "we eat them all" insectoid race but they can be interacted and negioated with. Somethign that amazes me is that the Thoraxians, while considered the cruelst and worst race of all, are doing trading deals with other races and the Burlusts don't.
Poor Burlusts, even insects are more civiliced than them.
