Install freeciv-client-gtk by entering the following commands in the terminal:
sudo apt update sudo apt install freeciv-client-gtk
Description:
Civilization turn based strategy game (GTK+ client)
Freeciv is a free clone of the turn based strategy game Civilization. In this game, each player becomes leader of a civilisation, fighting to obtain the ultimate goal: the extinction of all other civilisations. . This is the GTK+ 2 version of Freeciv. It is the most sophisticated and recommended client to play the game.
Homepage: http://www.freeciv.org/
Version: 2.5.10-1
Section: universe/games