Welcome to Principia
Principia is a physics-based sandbox game. Build and play advanced contraptions, circuiting, minigames, robot adventures and more. Open source, free and available for Windows, Linux, Android and more, download it today.
This site is the new community site for Principia. When you have installed Principia, enjoy the levels others have created, and register in order to upload your own levels and interact with the community.
Also check out...
And the Official community site archive, an archive of old levels spanning from 2013 to 2018.
Featured levels
Latest news More
- Mar 22, 2025 – Please help to test Principia
- Aug 1, 2024 – New contest: Destruction Frenzy
- Jul 12, 2024 – Principia 2024.07.12
- Jun 28, 2024 – Principia 2024.06.28
- May 18, 2024 – Principia is now on F-Droid!
Top rated levels More
Latest custom levels More
Latest adventures More
amirahmad81 commented on Super Smash Robots: 1 day ago
Maybe a version without the haaax and the jetpack, and with a scoreboard will be exiting!amirahmad81 commented on golem mk3: 1 day ago
An interesting level after a while! Wait for improvements :)nomad commented on Alu: 2 days ago
This ALU from turing complete. Im trying to recreat full proccesor architectur from this gameGlados commented on Alu: 3 days ago
You could just do OR, AND, NOT and XOR. For the arithmetic part and the rest of the computer, try Turing CompleteROllerozxa commented on Apparatus level 34 in Principia: 5 days ago
This level should now be fully playable as of commit 2421a1c, if you're running a development version of the game. New release soon™️. :)ROllerozxa commented on Apparatus level 34 in Principia: 5 days ago
I'm using this level as a test for reimplementing puzzles. Currently if you run the latest development version of Principia you can open a puzzle in the sandbox and play it from there, but I haven't fixed playing puzzles directly from a community site yet.Glados commented on Raccoon pixel art: 7 days ago
Yes, I encoded the images using a custom Python code. Try making a GIF by importing several pictures and switch between them fast enoughROllerozxa commented on Raccoon pixel art: 9 days ago
@Glados hmm, this one? :)