Games similar to X-COM: Terror From the Deep:

Here, order is maintained by the Church of Seiros, which hosts the prestigious Officer’s Academy within its headquarters. You are invited to teach one of its three mighty houses, each comprised of students brimming with personality and represented by a royal from one of three territories. As their professor, you must lead your students in their academic lives and in turn-based, tactical RPG battles wrought with strategic, new twists to overcome. Which house, and which path, will you choose?

XCOM 2 is the sequel to XCOM: Enemy Unknown, the 2012 award-winning strategy game of the year. Earth has changed and is now under alien rule. Facing impossible odds you must rebuild XCOM, and ignite a global resistance to reclaim our world and save humanity.

In this FPS, you travel across a remote island off the coast of Russia ripping through space and time, and are given your own Time Manipulation Device of which you use to vaporize enemies. You can upgrade your TMD, yourself, and weapons throughout the campaign which is reminiscent of every modern shooter from the Call of Duty Modern Warfare and World at War series to Half Life 2, and F.E.A.R. Time is power. Multiplayer included but is no longer filled with an active community.

You’re Robert Hawkins, an American stuck deep in Nazi controlled territory during the height of WWII. It’s up to you whether to fight your enemies face to face, snipe them from afar, or sneak past and sabotage their positions. Join the fight against the evil Third Reich in open-ended missions across war torn Europe.

Dr. Gordon Freeman doesn't speak, but he's got a helluva story to tell. This first-person roller-coaster initiated a new era in the history of action games by combining engrossing gameplay, upgraded graphics, ingenious level design and a revolutionary story that may not be all that it seems, told not through cutscenes, but through the visual environment.

Rogue Warrior is a character-driven, first-person-shooter, featuring Richard Demo Dick Marcinko's explosive personality in an action-packed single player campaign, and intense multiplayer combat.

For a millennium, three opposing forces of humanity--the Cybran Nation, the Aeon Illuminate and the United Earth Federation--have fought a bitter and bloody war over conflicting and unwavering systems of belief. There is no room for compromise. No room for mercy. No room for anything but the complete eradication of anyone with opposing belief systems. Labeled the Infinite War, this horrific conflict has shattered a once peaceful galaxy and only served to deepen the hatred and schisms between the three factions. Now, after centuries of struggle, the battle for supremacy has at long last reached a turning point. You are a Supreme Commander, and only you have the power to bring the Infinite War to an end once and for all. Set in the 37th century, Supreme Commander signals the next evolution in the RTS genre by being the first strategy game to deliver a truly strategic and tactical experience

The player can take control of American, British, Russian, or German forces to play out battles that are set in World War II. The game is primarily a strategy game, but the player can take control of his or her forces and direct them with the keyboard and mouse for additional depth of control.

X-COM: UFO Defense is a strategy game that combines tactical combat with base management and global defense. Players lead an international organization tasked with defending Earth from an alien invasion. The game unfolds on two levels: a global view where players manage resources, research alien technology, and intercept UFOs, and a tactical combat mode where squad-based battles occur. Players recruit and train soldiers, build bases, and develop new weapons and equipment based on recovered alien technology. Missions involve turn-based combat against aliens in various environments, with permadeath adding tension to each engagement. As the alien threat escalates, players must balance research, defense, and offensive operations to protect Earth's nations from panic and alien infiltration. X-COM: UFO Defense's blend of strategic depth, tactical combat, and atmospheric tension creates a compelling gameplay experience in the face of a global alien threat.

They're back...only this time the heinous aliens are out to destroy Earth and rule the new frontier. As X-COM commander, it's your sole duty to protect humanity and the prized mining operations in outer space. You must strategically equip your X-COM fighters, amass a formidable arsenal and then fulfill your mandate by going head-to-head with the devious element. The action is fast. And the opposing forces are wicked. But if you are smart, diligent and quick, you will prevail in a masterfully fought campaign to save our planet from perilous collapse.