Free games like Terraforming Mars
Below are 8 free-to-play Steam games similar to Terraforming Mars, ranked by player overlap and content similarity. No purchase or Steam login required to view the list. Every pick is a full free-to-play title — not a demo, trial, or time-limited giveaway. imho.run's catalogue refreshes daily, so newly free or newly popular titles surface here without manual editing.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Terraforming Mars page.
Ranked picks
- 1
The Lab
Free-to-play alternative to Terraforming Mars — no purchase or trial window.
Welcome to The Lab, a compilation of Valve’s room-scale VR experiments set in a pocket universe within Aperture Science. Fix a robot, defend a castle, adopt a mechanical dog, and more. Still not sold? It’s free!
- 2
Die in the Dungeon: Origins
Free-to-play alternative to Terraforming Mars — no purchase or trial window. Shares Strategy with Terraforming Mars.
Fight your way through a mysterious dungeon in this deck-building, turn-based roguelike game where you don't use cards, but DICE! Deal with enemies by combining dice on your board, boost their effects with magical relics, and discover the story behind Die in the Dungeon!
- 3
Jigsaw Puzzle Dreams
Free-to-play alternative to Terraforming Mars — no purchase or trial window.
Beautiful Multiplayer Jigsaw Puzzle game where you can design the room you play in!
- 4
The Last Sovereign
Free-to-play alternative to Terraforming Mars — no purchase or trial window. Shares Strategy with Terraforming Mars.
Explore a world torn between armies of lust and purity in which everything is more complex than it seems, deciding the fate of nations through might, politics, and finance. Every decision matters in an intricate saga that tracks thousands of variables.
- 5
Counter-Strike 2
Free-to-play alternative to Terraforming Mars — no purchase or trial window.
For over two decades, Counter-Strike has offered an elite competitive experience, one shaped by millions of players from across the globe. And now the next chapter in the CS story is about to begin. This is Counter-Strike 2.
- 6
Dota 2
Free-to-play alternative to Terraforming Mars — no purchase or trial window. Shares Strategy with Terraforming Mars.
Every day, millions of players worldwide enter battle as one of over a hundred Dota heroes. And no matter if it's their 10th hour of play or 1,000th, there's always something new to discover. With regular updates that ensure a constant evolution of gameplay, features, and heroes, Dota 2 has taken on a life of its own.
- 7
Tom Clancy's Rainbow Six Siege
Free-to-play alternative to Terraforming Mars — no purchase or trial window.
Rainbow Six® Siege is the reference in tactical team shooters, where elite strategy and execution triumph. Enjoy free access to Quick Match, Unranked, and Dual Front game modes with a selection of operators.
- 8
SCP: Secret Laboratory
Free-to-play alternative to Terraforming Mars — no purchase or trial window.
Deep within a secure underground facility, a sudden containment breach allows many of the secured anomalies to escape from their chambers. Assist the Foundation in re-securing the facility, help the Insurgency in their goal to capture it, or wreak havoc as an SCP in a frantic bid to escape.