GENESE is a living planet simulation running in the browser.
You start with a barren desert planet and three tools: rain, terrain, and sunlight. Build mountains and canyons, make it rain, and watch the water carve its own rivers and fill lakes in real time. Vegetation grows where there's moisture, with different biomes based on altitude and proximity to water. Crank the sun up and everything dries out and burns. Pull it down, snow and ice take over.
The water cycle eventually runs on its own, clouds form, drift toward the peaks, and rain again.
Try it out here : https://omma.build/p/tiny-planet-in-space-h519np 😊