Look under the "Simulation" tag for no-cost options.
If you are looking for a game where you simulate or interact with alien life, there are several popular and highly-rated titles (though most are paid, not "free download" in a legal sense): alien-life-simulator-pc-game-free-download
You control a herd of strange creatures on a surreal alien world. Look under the "Simulation" tag for no-cost options
It looks like you might be looking for a specific PC game or perhaps a research paper with that title. Since "alien-life-simulator-pc-game-free-download" sounds like a specific file name or a search string, I’ll help you narrow it down based on the most likely interpretations: 1. You're looking for a Game called "Alien Life Simulator" You're looking for a Research Paper or Article
Focuses on breeding and evolving your own animal tribe to survive in different biomes. 2. You're looking for a Research Paper or Article