Earth Sim

A small world with a lot going on

Start with a handful of people and see what becomes of them. Follow a life, watch an idea spread, and see a camp grow into a village. Help when things go wrong, or let the world find its own way.

Single-player civilization sandbox. Free browser demo. Full offline game: US$2.99.

Try the free demo

Play the Welcoming world here or at sim.longgbot.cv. There is no time limit. Discoveries, families, seasons, 1x and 2x speeds, and save/load are included. You can add people or restart if the population dies out.

Get the full sandbox

• Three starting worlds: Welcoming, Standard and Challenging.
• Custom seeds for different landscapes.
• 5x and 10x speeds for watching longer histories.
• Creature tools to heal, feed, warm or edit, plus animal spawning.
• Offline play in a desktop browser.
• A field guide with nine optional experiments and a notes template. Compare communities, follow one life through winter, or replay a world with a different intervention.
• Future updates published to this same game, included with your purchase.

More room to grow in the full edition

Four later crafts build on the knowledge your communities already have. Pottery slows food spoilage. Masonry helps shelters last. Built hearths use less fuel. Soil care improves planted soil and crop selection. Look for clay jars, stone footings, enclosed hearths and garden beds as those crafts spread.

Community progress shows the discoveries, practice and earlier crafts each community needs. These are earned through play, not granted instantly when you buy.

Places worth remembering

The full edition now includes meeting houses, workshops, care houses, markets, shrines and memorial grounds. People bring materials, gather what is missing and repair the places they use. Each has its own founder, visitors and history.

A workshop needs a skilled teacher or a tool to repair. Care takes a patient, a caregiver and supplies. Markets exchange real surplus goods. Shrines grow local traditions from memories of warmth, water, food or loss, and repeated gifts can change their customs. Memorial grounds remember named people and their surviving families.

Open World tools > Places & traditions to see what happened, what is still needed and who was involved. Useful visits are counted separately from completion. Quiet buildings remain quiet until people have a reason to use them.

Watch progress take shape

Learned crafts change the look of shelters and food stores. Timber homes, farmhouses and settlement paths make a growing community easier to follow. Population has no fixed 160-person birth ceiling; food, warmth, health and local crowding still matter.

Chronicle Highlights keeps discoveries and turning points easy to find. Routine lessons are grouped in All events, and new entries wait while you read.

Your purchase and updates

Pay once. No subscription. Keep your purchase email or claim the game on your itch.io account to return to your downloads. You do not need to buy each update.

The full game is a ZIP download. Extract it and open index.html in your desktop browser. Download again only when you want a newer version or another copy. The embedded player on this page is the free demo.

Bring your world with you

Before switching editions or updating, open World tools > Saves and backups > Download current world. Open the full game and import that JSON file in the same panel. Browser saves do not move automatically between websites or folders. Keep the old folder until your new version and save work.

Your first few minutes

1. Choose Find human, then Follow.
2. Read their current action and needs. Keep warmth high; low hunger and thirst are good.
3. Visit a Chronicle discovery, then save before you leave.

Alpha v0.9.5

Still in development. Large populations and high speeds can run slowly. Chrome has had functional testing; Edge and Firefox need more testing. A reported browser crash is still being investigated. The FPS counter can read too high on slow frames.

New in 0.9.3

Collapse either sidebar with its arrow icon. Choose a narrower panel and compact spacing in World tools > Panel settings. Your layout stays between sessions.

Animal families now track both parents and generations. Species mature at different rates, bears forage as well as hunt, and owls rest in daylight when safe and fed. Human body traits explain their tradeoffs, and relationship labels make bonds easier to read. The simulation uses compressed time rather than real-world biological ages.

Made by Long Trinh

Leave a comment with your version, seed and what happened. Keep personal information out of public comments.