List of the top Sci-fi games:

Jetboy is a retro supercharged jetpacking pixel shooter with a pumping metal soundtrack.

The ultimate space capital ship combat compendium is the evolution of hard core space combat sims. The only game of its kind currently in existence.

In the distant future, the X universe faces a period of profound and irrevocable change. While the universe stumbles towards an uncertain future, countless adventures await as new enemies rise in search of power.

The year is 2047. A massive nuclear fireball explodes high in the night sky, marking the dramatic beginning of the Third Tiberium War and the long-awaited return of the most groundbreaking Real-Time Strategy franchise of all time.

Halo: Spartan Assault brings the excitement of Halo combat to Steam for the very first time. Battle your way through 30 action-packed missions against the Covenant as you explore the origin of the Spartan Ops program featured in Halo 4. *DirectX feature level 10 required. *

Battlefleet Gothic: Armada is the RTS videogame adaptation of Games Workshop’s classic tabletop game, pitting the Chaos, Imperium, Eldar, and Orks against each other in visceral space-battles.

Ancient Space is a story driven single player real time strategy game where you take command of a fleet embarking on a scientific mission to chart undiscovered reaches of space called ‘The Black Zone’. Overcome overwhelming odds and fight for your life and the survival of your ship and its crew.

Defense Grid: The Awakening is a unique spin on tower defense gameplay that will appeal to players of all skill levels. A horde of enemies is invading, and it's up to the player to stop them by strategically building fortification towers around their base.

The XCOM: Enemy Unknown - Slingshot Pack is Now Available!

The year is 1962 and the Cold War has the nation gripped by fear.  A top-secret government unit called The Bureau begins investigating a series of mysterious attacks by an enemy more powerful than communism.

Interstellar Space: Genesis is a turn-based space 4X strategy game in which you attempt to build a thriving galactic empire. Discover mysteries among the stars, colonize worlds, and engage enemies in tactical turn-based combat on your journey to becoming the ruler of the galaxy!

ENDLESS™ Space 2 is a Strategic Space Opera, featuring the compelling “just one more turn” gameplay, set in the mysterious ENDLESS™ Universe. As the leader of your civilization, will you impose your vision and build the greatest stellar empire?

Half-Life Deathmatch: Source is a recreation of the first multiplayer game set in the Half-Life universe. Features all the classic weapons and most-played maps, now running on the Source engine.

Azulgar: Star Commanders is a Sci-Fi open world sandbox game that puts you in a command of your own custom made space ship. Explore aftermath of the Azulgar event that reshaped the face of the solar system.

Halo: Spartan Strike makes you a Spartan supersoldier battling evil forces. Delve into 30 challenging missions through cities and jungles using a devastating arsenal of weapons, abilities and vehicles including the iconic Warthog against the Covenant and Promethean enemies. *DirectX feature level 10 required*

ENDLESS™ Space is a turn-based 4X strategy game, covering the space colonization age in the Endless universe, where you can control every aspect of your civilization as you strive for galactic domination.

As Commander Shepard, you lead an elite squad on a heroic, action-packed adventure throughout the galaxy.

Take on the role of Nora Harwood, member of Everreach’s Security Division, on a mission to secure the colonization process of Eden and investigate mysterious incidents! Everreach: Project Eden is a fast-paced, story-driven action-RPG set on the visually stunning Planet Eden.

What if someone knew your mind better than you did? The Swapper is an award-winning, narrative driven puzzle game set in the furthest reaches of space.

Etherium is a real-time strategy game set in a science-fiction universe, where three factions battle it out for a mysterious and rare resource known as ‘Etherium’.

A game that will show gamers the deepest, darkest side of the Force in a story that puts them on a collision course with Luke Skywalker himself.

Solve challenging cable-based puzzles and uncover what really happened to the crew of The Alabaster. Now with Hint System (for those ultra tricky puzzles).

A ground-based RTS prequel to the classic Homeworld games. Assemble your fleet and lead them to victory on the shifting sands of Kharak in this compelling strategy game for PC from Blackbird Interactive.

Driven to the brink of extinction on ice-covered wastelands, humankind fights to survive. Battle to survive against gargantuan alien Akrid and treacherous Snow Pirates on the vast and frozen landscape of EDN III.

The ascendant spacefaring 4X strategy game returns! A new chapter in the epic Master of Orion saga is poised to once again capture the imaginations of millions of gamers.

In Star Trek Online, the Star Trek universe appears for the first time on a truly massive scale. Players take the captain's chair as they command their own starship and crew. Explore strange new worlds, seek out new life and new civilizations, and boldly go where no one has gone before.

Captain Gail Pilgrim has been flying starships since she was a kid, ferrying passengers between planets and space stations across the galaxy. She has no reason to expect that this latest trip to Alpha Centauri will be anything special, even if her passengers are a little more diverse than usual....

Deus Ex: The Fall is set in 2027– a golden era for science, technology and human augmentation, but also a time of great social divide and global conspiracy. Powerful corporations have seized control from governments and command the drug supply needed by augmented humans to survive.

Parcel is an atmospheric block-pushing puzzle game where your goal is to solve interlocking laser puzzles by using the unique abilities of different characters. Switch between members of your team of postpeople and make your way through mind benders in a charming, ridiculous cyberpunk future!

Approximately 20 years after the events depicted in Deus Ex, The World is only beginning to recover from a Catastrophic worldwide depression. In the Chaotic period of recovery, several religious and political factions see an opportunity to re-shape a worldwide government to their agendas, understanding that the right moves now could...

The Turing Test is a challenging first-person puzzle game set on Jupiter’s moon, Europa. You are Ava Turing, an engineer for the International Space Agency (ISA) sent to discover the cause behind the disappearance of the ground crew stationed there.

Set in futuristic Tokyo, take control of the robotic community before they control everything!