Sins of a Solar Empire: Trinity®

Together, these mechanics make the galaxy feel less like a collection of isolated armies and more like a shifting political environment.

Performance with the default graphics configuration is considered suitable, and the game can run successfully on SteamOS.

Multiplayer is great especially if the game drags on for 2 hours (multiplayer games are often short: you either get rushed or you lose all your planets with doomsday weapons).

It works really nice if you play it with friends and cooperates with eachother.

The combat takes place on epic scales, it can be incredibly nuanced and technical depending on how in depth you want to get, and I think that it speaks volumes to it's balance and staying power that the SoSE subreddit is still very active after several years of its release, as is the modding community.