Worldsmith

Dial in a planet's distance, speed and mass, hit launch, and hold its orbit inside the green habitable zone.

How to play

Adjust three sliders to set up your planet, then launch a deterministic gravity simulation that plays out in real time. A green ring marks the habitable zone; your score climbs the longer the planet stays inside it. A run ends if the system collides or ejects the planet, or when the time budget expires.

• Too slow and the planet spirals in; too fast and it flies away
• The green ring is the band you're trying to keep the orbit within
• The planet leaves a trail so you can read whether its orbit is stable

Controls

• Desktop: drag the distance, speed and mass sliders, then click Launch
• Phone & tablet: drag the sliders and tap Launch — fully touch-friendly

Game modes

• Daily: one shared seeded star system each day
• Practice: endless new setups

Tips & strategy

• A near-circular orbit (matching circular orbital velocity) holds the green zone longest
• Set distance first, then fine-tune speed to round out the ellipse
• Higher mass tugs the system harder — adjust speed to compensate

What you'll learn

Worldsmith is an orbital-mechanics sandbox driven by a genuine N-body gravity model, letting you feel how gravity shapes orbits.

• Skills: orbital mechanics, gravity, N-body motion, systems simulation
• Best for: roughly grades 9–12 (ages 14+)
• For parents & teachers: real gravitational physics to play with and explore.

About Worldsmith

Worldsmith is an original orbital-mechanics sandbox driven by a genuine N-body gravity model. It's free to play directly in your browser.

A free, original browser game on PlayPendium — no download, no install. Browse all games →