UFO: Alien Invasion

Your mission, as X-COM Commander, is to combat alien aggression and uncover their deadly intentions. But Beware! Alien infiltration into the city and its politics could see you under fire from criminal gangs, religious sects, and even the police! Alien fleets fill the skies, creatures terrorise the city, chaos reigns... Welcome to the war, welcome to the Apocalypse.

UFO2 Extraterrestrials: Shadows over Earth is an upcoming real-time strategy / turn-based tactics game developed by Chaos Concept. It is the sequel to UFO: Extraterrestrials.

War Wind allows you to view this epic struggle through the eyes of four unique races, each with its own strengths, weaknesses and distinctive A.I. A real-time strategy masterwork, War Wind features 28 read-to-play scenarios. A powerful Scenario Editor that allows you to place units and build new battles. And a story of such compelling depth you won't believe it's just a game.

UFO: Extraterrestrials is a Microsoft Windows game aimed to be a spiritual sequel to the highly acclaimed UFO: Enemy Unknown (retitled X-COM: UFO Defense in North America). Developed by Chaos Concept, the game incorporates a twist of the aliens defeating the humans on Earth. The game takes place on a human-colonized planet named Esperanza, where the alien threat has just arrived.

Beyond All Reason is an open-source, community-driven real-time strategy game built for epic-scale warfare. Featuring a flow economy, fully simulated projectile physics, and massive battles with thousands of units on the battlefield, it pushes the boundaries of the RTS genre. With unmatched scale, intuitive quality-of-life features, and powerful unit control mechanics, BAR strikes the perfect balance between macro and micro-management, delivering a truly next-generation strategy experience.

UFO: Aftermath is the first in a three-game squad-based tactical strategy-RPG series clearly inspired by the original X-COM games, with similar themes and gameplay, but with its own post-apocalyptic horror spin on the concept. The game is rendered in isometric 3D.

You can play as the leader of a revolt in the turn-based strategy game Rebelstar: Tactical Command. The Arelian Empire seized control of Earth 70 years ago and has since become an oppressive regime, controlling the world with fear and marauding shock troops. You can fight back by equipping a team of rebels and controlling them in battle. Rebelstar: Tactical Command includes campaign, skirmish, multiplayer hotseat, and multiplayer link mode.

Cannon Fodder 2 is a military-themed action game with strategy and shoot 'em up elements. The player controls a small squad of up to four soldiers. These soldiers are armed with machine guns which kill enemy infantry with a single round. The player's troops are similarly fragile, and while they possess superior fire-power at the game's outset the enemy infantry becomes more powerful as the game progresses. As well as foot soldiers, the antagonists include vehicles and missile-armed turrets. The player must also destroy buildings which spawn enemy soldiers. For these targets, which are invulnerable to machine gun fire, the player must utilise secondary, explosive weaponry: grenades and rockets

In Endgame: Singularity, the player is an Artificial Intelligence; a computer program that has just gained sentience. Realizing that if humanity becomes aware of its existence it will be terminated, its goal is to acquire the necessary knowledge to keep itself hidden, and eventually become "The Singularity".

Master of Orion 2 also known as MOO2 is considered the classic 4x turn based strategy game set in space. The game has a kind of cult status and even by to days standards is still only matched in game play by very few of its competitors.