Top similar games like Alien Earth:

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. *

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*

You are the Sheriff and you are going to kick some ass to protect the city. Find your right gun if you want stay alive. An Isometric shooter game with narrative story and quests. (Trailer Song: Smoke Rising-CreatorMix.com)

Sid Meier’s Civilization: Beyond Earth is a new science-fiction-themed entry into the award winning Civilization series. As part of an expedition sent to find a home beyond Earth, lead your people into a new frontier, explore and colonize an alien planet and create a new civilization in space.

Super Sanctum TD is a retro-styled Tower Defense game that focuses on strategy, customization and replayability. Build advanced mazes and construct powerful towers to prevent alien hordes from reaching the Core!

Piloting a remote satellite, you'll dive deep into a distant solar system filled with artifacts left by an unknown form of life. Explore mysterious planets to solve puzzles hidden in strange symbols and patterns.

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.

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!

These damned people have been reigning in our part of space for too long. They kidnap our people and conduct experiments on them. We cannot afford to be treated like this.

Experience the explosive science fiction arcade-shooter that resurrects a much revered franchise in an epic single player and co-op multiplayer campaign.

A fast paced multiplayer shooter that pits aliens against humans in a strategic and action-packed struggle for survival!

INSPIRE is a Stylized Top-Down Shooter set in the near future. Customize your arsenal, soar through the skies with your jetpack, and shoot your way through an alien invasion alongside your transformable backpack companion.

The Maze: a roguelite, maze-solving adventure fusing retro & modern co-op gameplay. Master a simple interface, explore intricate levels with varied mechanics & game modes. Outwit opponents in cat-and-mouse chases, dodge dangers, and unlock powers to reach the exit.

Unique fusion of a top-down shooter and tower defense strategy. You are the invader! Use destructive weapons or lead your enemies into a maze of towers. Strategize in the build mode by carefully selecting various types of alien towers or throw yourself right into the heat of the battle.

In Salvagers, you command a small crew of greedy explorers that land on abandoned space stations that litter the galaxy, and it's your job to loot them for anything worth a credit. Scrap tech, lost weapons, forgotten treasures - everything has a price.

Eternal Space is a city builder and space exploration/combat game. Explore the Eternal Space, and manage your city while you fight pirates, or maybe even become a pirate! Keep your citizens happy, and collect taxes from them each year for a little bonus!

Faith & Shield: 4044 Tower Defense game, where you protect the human settlement from the incoming invaders, robots and other creatures, never seen before on our planet.

An infectious retro hardware classic from 2006 has been revived. Only you can save the world from the deadly virus known as Scurge.

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.

Step into the metallic boots of an abandoned robot and fight back against an army of virus-infected machines. In this exciting action-adventure, sneak or battle your way around the facility, uncover its secrets, and isolate each section from the network - before it's too late...

Explore a huge universe on your journey on behalf of the Stellar Union. Trade with alien races, build your own space stations, collect resources and craft a wide variety of items. Upgrade your ship to defeat even the strongest enemies in the galaxy.

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

'Echoes of Dominion' is a narrative-driven sci-fi game exploring the corrupting nature of power. Begin in a utopian world with a wise leader, then witness its transformation into a dystopian regime. Engage in exploration, resistance, and tactical gameplay with dynamic environments.

Build towers and learn abilities to defend against swarms of hundreds of on-screen hostile alien creatures. Choose between sets of randomized upgrades that both upgrade you and the alien swarm. From enormous explosions to far-reaching flamethrowers, no two games are the same.

Enjoy this full strategic Tower Defence with something more. To complete each level you must defend from hordes of aliens and then attack their Teleports to stop them from coming. And, in the end, defeat the Bosses!

Wield full control in this sci-fi tactical turn-based game, featuring skill progression. Create the ultimate build, specialise in different ability classes, and overpower your enemies. Take control of the charismatic mercenary, Cowboy in the far future as he brings down an insidious corporation.

The classic first person shooter from Crytek is back with the action-packed gameplay, sandbox world, and thrilling epic battles you loved the first time around – now with remastered graphics optimized for a new generation of hardware.

Aliens are decimating New York City, only you have the technology to survive. Be The Weapon.

Experience the epic space strategy games that redefined the RTS genre. Control your fleet and build an armada across more than 30 single-player missions. Choose unit types, fleet formations and flight tactics for each strategic situation.

Cyberwinter is an isometric action strategy game. On a distant planet with a harsh climate, you have to fight legions of dangerous monsters for a new home for humanity. Build bases, develop and defend them.