Sim Planet

Shape a world. Watch it evolve.

Sim Planet is a planetary sandbox where climate, continents, ecosystems, and civilizations influence one another. Create a world, change its conditions, and watch the consequences unfold.

Raise mountains, reshape coastlines, adjust sunlight, and introduce life. Watch ice spread or retreat, vegetation flourish, animal populations evolve, and continents slowly drift. Found a settlement and follow its people as they expand, share food, develop technology, and face environmental pressures.

Explore freely or try guided experiments: thaw a frozen planet, sustain a civilization, or help an industrial society recover after its fuel runs out.

• Explore your world as a globe or flat atlas.
• Switch between climate, terrain, wildlife, and civilization maps.
• Zoom into regions and follow individual settlements.
• See recorded food trades and settler movements.
• Compare earlier coastlines, ice, and vegetation.
• Use the “What changed?” summary to discover the past decade’s main changes.
• Export your worlds and capture screenshots of your experiments.

Made with ChatGPT and Codex

Sim Planet was created by Joe with assistance from ChatGPT and OpenAI Codex, including programming, writing, and development support. The illustrated cover and optional Pond experiment’s backdrop were generated using ChatGPT’s image-generation tool. The planet maps and simulation graphics are drawn procedurally by the game.

An evolving prototype

Sim Planet is still in development. Its systems are simplified and accelerated for experimentation and play, rather than scientific prediction.

Play directly in your browser. Saves stay in your current browser and device; use Export to keep a separate copy or move your world elsewhere.