Single-player games like Colony Siege
Below are 12 single-player Steam games similar to Colony Siege, 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 Colony Siege page.
Ranked picks
- 1
Rise of Nations: Extended Edition
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy and Simulation with Colony Siege.
Rise of Nations is back! Play the updated classic with full Steamworks integration and enhanced features!
- 2
The Riftbreaker
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
The Riftbreaker is a solo or Co-op base-building, survival game with Action-RPG elements for up to 4 players. Hack & slash countless hordes of enemies. Build up your base, craft powerful weapons and research new inventions to survive.
- 3
MarZ: Tactical Base Defense
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
Build your defense base to fight back the undead hordes of Mars and secure the future of the red planet. MarZ is a game of strategy and tactical defense where you must carefully manage your crew and resources as you try to uncover the terrible secrets of the undead.
- 4
Supreme Commander
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
For a thousand years, three opposing forces have waged war for what they believe is true. There can be no room for compromise: their way is the only way. Dubbed The Infinite War, this devastating conflict has taken its toll on a once-peaceful galaxy and has only served to deepen the hatred between the factions.
- 5
Empires Apart
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
An exciting free-to-play Real Time Strategy game set in medieval times. Uniquely designed factions, customization options, singleplayer and multiplayer gameplay. Gather resources, raise an army and lead your civilization to victory in a classic RTS, brought to the modern age.
- 6
AI War 2
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy and Simulation with Colony Siege.
The most devious and acclaimed artificial intelligence in strategy gaming is better than ever. A grand strategy/RTS hybrid that reverses many conventions of both genres. Take territory without attracting attention, build your empire with care, and adapt to an ever-evolving galactic battleground.
- 7
Stronghold: Warlords
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy and Simulation with Colony Siege.
Besiege Great Khans, Imperial warlords and Shōgun commanders in Stronghold: Warlords, the latest 'castle sim' from Firefly Studios. Command AI warlords across the battlefield as you build a castle economy and new gunpowder-fuelled siege engines!
- 8
Siege of Centauri
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
Defend against thousands of enemies in this explosive tower defense game. Deploy upgradable towers and unleash powerful orbital abilities as you try to protect Earth's first colony world from destruction.
- 9
DG2: Defense Grid 2
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
Great strategy is timeless. Build, adapt, and defend across dynamic maps, solo or online - every session brings new strategies, new solutions, and new surprises. Now is the perfect time to enter the grid.
- 10
Grey Goo
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
Fight for control of a frontier world. Gather resources, build your base, and command your forces in battle. Survive long enough to unleash your ultimate weapon - THE EPIC.
- 11
X-Morph: Defense
Single-player alternative to Colony Siege — playable solo, no multiplayer required. Shares Strategy with Colony Siege.
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.
- 12
MORPH
Single-player alternative to Colony Siege — playable solo, no multiplayer required.
Race to the finish! A short 2D platformer! Collect metal to upgrade your health and find new moves to use hidden in the levels!