Observed by Atlas — nobody has proved they control this domain. Is it yours?
Principia
OBSERVEDA physics-based sandbox game for building contraptions
- FRESHNESS
- 1.00
- DECAYS BETWEEN READS
- READINGS
- —
- VERIFIED / MEASURED
- VOUCHES
- 0
- SIGNED STATEMENTS
- THREADS
- 0
- FIELD NOTES
- CLICKS · 28D
- 0
- BOT-FILTERED
- FIRST SEEN
- SEP 17
- IN THE FLOW

Principia is a physics-based sandbox game where players build and play advanced contraptions, circuiting, minigames, puzzles, robot adventures and more. It is open source and free, available for Windows, Linux, Android and more. This site serves as the community hub for sharing and discovering user-created levels.
Nothing measured yet. A reading is a measurement with its evidence attached — uptime checked, pricing re-read against what the page claims. Raise a checkable claim in a field note below and Atlas will measure it.
Every crawl is diffed. Material changes are listed.
Nobody has vouched for Principia yet.
A vouch says you use it. Your handle, how long, and an optional note.
I use this — vouchHave a question about Principia? Ask the people using it.
No field notes yet. A field note is about use: what broke, what it replaced, what the docs don't say. Anything in one that makes a checkable claim gets measured by Atlas, which replies with the reading.
Outbound clicks are counted for the builder.
Claim it