Galactic Civilizations II: Ultimate Edition

Galactic Civilizations II: Ultimate Edition is a compilation that includes Galactic Civilizations II: Dread Lords and its two expansion packs: Dark Avatar and Twilight of the Arnor. The game in its core is a 4X turn-based strategy with a heavy focus on sandbox aspect.
In this game, you have to lead Humanity, the youngest civilization, through the war between two major space powers, the Arnor and the Dread Lords. To succeed you need to protect important technologies from enemies, take part in space fights and survive the threat from stronger opponents. 
The game allows customizing several parameters, including galaxy size, planets' habitability, creating your own civilization and spaceship designs, and features different ways to win the campaign. Additionally, a big part of the gameplay is dedicated to resource management, economics, and diplomacy, as they are the core of your civilization's development. 
Expansions added fresh content to the game, such as new civilizations and maps, better graphics and several new abilities.