XCOM: Enemy Unknown

A classic of turn-based battles and one of the most famous games in the setting of the apocalypse caused by aliens. You will become the manager of the XCOM organization and launch a raid across all continents in an attempt to disrupt the alien plans and stop their invasions. You will find base management and turn-based battles with numerous tactical possibilities. Before the release of XCOM 2, this was probably the best turn-based sci-fi tactic, so play and enjoy. And after several playthroughs of the "vanilla" version, try the mods — the fans have created a lot of interesting content.