XCOM: Enemy Unknown

From the makers of the Civilization series comes a game about humanity’s final stand. Threatened by an unknown foe, the Earth’s governments come together to form a stealth paramilitary organization known as XCOM to combat this extraterrestrial assault. At the helm of XCOM, you command the global defense team in battle against a frightening alien invasion. Determine the destiny of the human race by building and co-coordinating a fully operational base, researching alien tech, formulating combat missions, and choreographing soldier movement in battle.