Single-player games like Cartonfall: Fortress - Defend Cardboard Castle
Below are 12 single-player Steam games similar to Cartonfall: Fortress - Defend Cardboard Castle, 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 Cartonfall: Fortress - Defend Cardboard Castle page.
Ranked picks
- 1
Idle Towers
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Strategy and Indie with Cartonfall: Fortress - Defend Cardboard Castle.
An idle survival game with tower defense mechanics. Build your own perfect defese and face infinite waves of enemies!
- 2
Acucalypse
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Action and Strategy with Cartonfall: Fortress - Defend Cardboard Castle.
Acucalypse is a management & strategy game where you will have to manage your resources in order to destroy the bunkers of your enemies and face their attacks. Build your bunker & planes with remains of human civilization and fill them with bombs to destroy your friend-emies!
- 3
Dig or Die
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Action and Strategy with Cartonfall: Fortress - Defend Cardboard Castle.
Crash land on a hostile planet where you'll have to build the strongest defenses if you wish to live to escape from it. But be warned... this planet is merciless. Build strong, and smart; else physics may flood or destroy your only hopes of survival.
- 4
Medieval Engineers
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Action and Strategy with Cartonfall: Fortress - Defend Cardboard Castle.
Medieval Engineers is a sandbox game about engineering, construction and the maintenance of architectural works and mechanical equipment using medieval technology. Players build castles; construct mechanical devices and underground mining. There is an entire planet to explore!
- 5
The Riftbreaker
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Action and Strategy with Cartonfall: Fortress - Defend Cardboard Castle.
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.
- 6
Broken Universe - Tower Defense
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Strategy and Indie with Cartonfall: Fortress - Defend Cardboard Castle.
Get ready to rethink all your defense strategies! Build barricades to stop monsters, or lure them into a maze and attack. A variety of stages that change each time depending on how you play them.
- 7
Wooden Battles
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Action and Strategy with Cartonfall: Fortress - Defend Cardboard Castle.
Build a wooden fort, place your units, watch the mayhem!
- 8
Conan Unconquered
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Strategy with Cartonfall: Fortress - Defend Cardboard Castle.
From the Command & Conquer veterans at Petroglyph comes the first ever survival RTS set in the savage world of Conan the Barbarian. Play solo or team up in multiplayer in Conan Unconquered’s action-packed co-op Mode where you build a shared stronghold and fend off the hordes together.
- 9
Cartonfall
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Indie and Simulation with Cartonfall: Fortress - Defend Cardboard Castle.
It was another night shift at your job in a warehouse, when a madman with a box on his head, took control over the complex. Now you are under his control, to get out of here you have to solve his wicked riddles and smash through his weird cardboard structures by using anything you find in the boxes.
- 10
Shape of America: Episode One
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Indie with Cartonfall: Fortress - Defend Cardboard Castle.
Shape of America is a story-driven, non-linear, turn-based role-playing game about politics. The story is set the United States in the late 1990s, you are a young man who unwittingly finds himself tied up in all the important economic and political changes of the period.
- 11
Cryospace - survival horror in space
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Action and Indie with Cartonfall: Fortress - Defend Cardboard Castle.
You are not a soldier. Not a fighter. Just an ordinary maintenance guy. Yet you have to fight. And you are forced to run. But chiefly: you must help the frozen crew survive on a spaceship. You are the only one who can save others. You are made a hero against your will. You become a leader. A slayer.
- 12
Cryospace: Prologue
Single-player alternative to Cartonfall: Fortress - Defend Cardboard Castle — playable solo, no multiplayer required. Shares Action and Indie with Cartonfall: Fortress - Defend Cardboard Castle.
You are not a soldier. Not a fighter. Just an ordinary maintenance guy. Yet you have to fight. And you are forced to run. But chiefly: you must help the frozen crew survive on a spaceship. You are the only one who can save others. You are made a hero against your will. You become a leader. A slayer.