Top similar games like Alpha One:

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.

Unleash hell as a xeno-hating soldier aboard a ship being hijacked by a hitherto undiscovered alien race. Xenoterrestrial is a top-down technical shooter that combines skill and strategy for a fast-paced, challenging experience offering customizable weapons, complex mechanics, and diverse enemies.

Conquer the galaxy in this arcade-like strategy game. Pick and send your generals to deploy the fleet in the far-off star sectors, mine resources, and upgrade your ships forgeries. Deities might interfere with your plans.

A Roguelike Tower Defense in space with missions to conquer. Can you hold against the spreading alien bosses? Build and upgrade towers against the corruption. Choose your technologies and warpspeed your way to victory.

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.

Amazing graphics. Countless different units. An addictive Battle Pass. We have none of those things. Just one carrier and as many tiny fighters as you can muster to hold back hordes of enemy fighters and bombers. Victory is not enough - you may win the battle, but still lose the war!

2D space shooter and turret defense come together to create the Planetary Defense System this world needs! Shoot down asteroids and aliens and survive the bosses in this arcade like game featuring customizable satellites, projectiles, and upgradable Cannon and Planet Shield systems.

Mow down the alien hordes, scout for resources and survive. Dreadnought is a mix of Action Tower Defense Survival and Shoot 'Em Up Bullet Hell where you control the ships turrets & defend against waves of enemies. Choose your weapons, upgrade your ship & brace yourself, the horde is coming.

Customize your Ships, Upgrade your fleet, and Command your way to victory in this ruthless rogue-lite tower defense/real time strategy hybrid. Take on an enemy that learns from your moves and adjusts its own path. Do you have what it takes to persevere?

Stellar Space is a new take on a classic arcade game with a modern, rogue-like, form for new players to enjoy!

Blast through waves of alien enemies in Project AionIX! Master your piloting skills, dodge, and survive in this fast-paced space shooter!

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!

A turn-based strategy game about managing the first human colony on the pumpkin planet.

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

In Battlestar Galactica Deadlock™ you’ll take command of the Colonial Fleet in defense of the Twelve Colonies during the First Cylon War. Lead many different types of ships in this 3D tactical game. Every decision counts, your strategy will be vital – can you ensure mankind’s survival?

Fly around, mine resources, expand your ship, build weapons and fight off aliens!

Pewt 'em Up! is a retro inspired arcade space shoot 'em up with lots of upgrades, achievements, extras and more.

You awaken in a space eroded by the abyss. Protect the light and press forward. Defeat the monsters within the abyss!

This is a 4x turn-base strategy game. You can develop your planet, expand your territory by colonizing and building space stations, research technology to unlock more ships, and ultimately discover and eliminate your enemies.

A sci-fi shoot'em'up game with heavy focus on upgrades experimentation, featuring two unlikely heroes that must work perfectly together, despite their share of secrets, to surpass their limits and succeed in eliminating a threat that might destroy both Earth and Andraxia if left unchecked.

Ultakia is a turn-based space 4X strategy game with distinctive resource management. Explore exotic systems and acquire powerful technologies. Exploit your planets, trade with other races and destroy those who stand in your way.

Engage in an intense space shooter that you can play in single-player or multiplayer with up to 6 players. Play a variety of different spaceships, each with their own unique stats, components, and playstyles!

Stop the Saturnians is a shooter inspired by classic arcade games. Dodge enemy fire, destroy procedurally generated alien waves and fight massive bosses. Collect resources in the midst of combat to upgrade your ship or improve Earth's defenses. Protect yourself and the planet both!

Join Captain Rijk as he attempts to escape from the clutches of one of the most villainous species in the galaxy. Help to uncover the horrors that are being carried out on the fringes of the civilised galaxy and become the divine being prophesised to inspire an uprising and destroy The Domain.

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.

Master time. Stop the Ooze. Outsmart a galactic infection in this high-speed, turn-based roguelike. Use your Chrono Shard to loop the timeline, leaving gear and upgrades for your future self. Craft your arsenal, evolve your skills into elite sub-classes, and turn every death into an advantage.

A turn-based free-move strategy game. Walk/Run/Sprint freely without the grids. Your attack could be countered so choose your next move wisely.

Blast aliens to pieces and start a rebellion in this fast paced pixel art top down shooter where sprinting kills.

Dwarf Star: 16 bit inspired game where mercenary go shoot shoot on evil alien guys who were accidentally fabricated by the government. Top down space shooter with a mission based structure. However, you can do these missions in plenty of different orders with different amounts of upgrades.

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!

Galactic Civilizations is a space based strategy game in which you are in control of humanity's destiny.

You’re stuck out in the middle of space alone in ship, see how long you can survive with endless enemy ships and do all it again.

Oh no! Anxiety Bot has found himself in a meteor field! Try to help him survive as long as possible in this cozy, laid back arcade shooter. How long can you keep him safe?

Cardalaxy is a card upgrading game with 4X inspiration and 5+ different victories.

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. *