Sword of the Stars: Complete Collection

Combat itself plays out in real time within fully three-dimensional space, offering a sense of scale and physicality that many turn-based strategy games lack.

The gameplay is deep and interesting, and rewards a player for playing well both tactically and strategically.

Graphics are great (although this is a game from the early 2000's, so don't expect cutting-edge graphics like games nowadays) and do a great job showing the pure scale of each game.

Multiplayer is just as good - coordinate with a friend or compete against them in 4X/RTT combined gameplay.

The learning curve is steep, and early mistakes can have long-lasting consequences, which may discourage players accustomed to more forgiving modern 4X titles.

While I'm at it, there's a ton of customization options for game setup, ranging from galaxy shape, amount of explorable planets, number of players, etc. along with the previous randomization leaves this game with a ton of replay value along with a lot of fun with friends.