Single-player games like Grey Galactic
Below are 8 single-player Steam games similar to Grey Galactic, ranked by player overlap. Every pick carries Steam's Single-player category, so multiplayer-only titles or always-online games don't sneak in. imho.run pulls the category data from Steam directly — Single-player here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Grey Galactic page.
Ranked picks
- 1
Negative Energy
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Strategy and Early Access with Grey Galactic.
Negative Energy is a tower defense game with basic RTS mechanics, where your goal is to defend the construction of a Dyson sphere, while fighting against waves of hundreds of enemies ships.
- 2
The Fall of Aether Station
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Action and Strategy with Grey Galactic.
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?
- 3
Space Alliance: Frontier
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Strategy and Indie with Grey Galactic.
Get ready to protect the entire solar system from an unprecedented threat - the D'Ahari, a race of insect-like aliens. Control an entire fleet of spaceships, trade with other races of an Alliance, and develop your own space station.
- 4
SYNCHRONIZERS: UNDEAD MARINES
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Action and Strategy with Grey Galactic.
"SYNCHRONIZERS: UNDEAD MARINES" blends high-quality Three-Lane Tower Defense with Reverse Tower Defense gameplay. Command your units in a thrilling narrative reminiscent of a StarCraft and Plants Vs. Zombies fusion! Your choices will forge the path to victory—or defeat.
- 5
Line Of Defense Tactics - Tactical Advantage
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Action and Strategy with Grey Galactic.
A real-time strategy combat game based on the world of the Line Of Defense. Command a team of four Galactic Command marines in highly classified missions in space and on planets.
- 6
Door Kickers 2: Task Force North
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Action and Strategy with Grey Galactic.
Command military Special Ops Teams in gripping tactical combat against a Middle East-based terrorist network. Sequel to RockPaperShotgun's "Best Tactics Game of 2014".
- 7
Calyx
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Strategy and Early Access with Grey Galactic.
A strategy game with a new kind of enemy, Calyx puts you in charge of a space mining outpost, locked in battle against powerful plant-aliens. Build your base, gather resources, assemble your forces, and take on the Calyx. With only an out-of-date AI for company, can you survive?
- 8
Iron Marines Invasion
Single-player alternative to Grey Galactic — playable solo, no multiplayer required. Shares Action and Strategy with Grey Galactic.
Prepare to take off, soldier! The galaxy needs your strategy! Prove your RTS expertise, explore an entire galaxy and defend it from a threatening invasion.