Spore

Post from the Dev team:
Hello everyone, I'm here from the Thrive development team to announce we've released the third major update since we started development of the Multicellular Stage, our second game stage. Why is it called 1.6 then? Because we completed everything up to planned release 1.6 in the past three months! And that means the Multicellular Stage is now about 60% completed.

Thrive is a open-source non-profit game that aims to be Spore-like in that it runs through stages from a single-celled organism to a space-born civilization while letting you edit and evolve your species along the way. But it also has a heavy emphasis on providing a convincing and interesting evolution simulation, so that the world changes around you. We also try to keep things scientifically accurate wherever we can, but the focus is on the gameplay experience.

This update in particular adds sexual reproduction, lets you make muscle cells and enables our automatic evolution system to create Multicellular species. But there are also many other additions and improvements, large and small.