Terraformers: First Steps on Mars is a free standalone version of Terraformers.

Lead the first human settlement on Mars! Earth is sending its first expedition to assess the viability of human settlement on Mars, with the long term objective of terraforming the planet and spreading life across its surface. You will have to explore the planet, exploit local resources and develop your colonies into large cities. But make sure to provide a decent living standard for your people to retain their support! Are you ready to lead mankind’s first steps on Mars?