Welcome to Principia
Principia is a physics-based sandbox game. Build and play advanced contraptions, circuiting, minigames, puzzles, 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.
Want to read more about Principia?
Also check out...
And the Official community site archive, an archive of old levels spanning from 2013 to 2018.
Apparatus player? Check out Principia for Apparatus Players on the Principia Wiki!
Featured levels
Latest news More
- 6 Jul 2025Follow Principia on YouTube
- 14 Apr 2025New contest: Puzzling Puzzles
- 5 Apr 2025Principia 2025.04.05
- 22 Mar 2025Please help to test Principia
- 1 Aug 2024New contest: Destruction Frenzy
Top rated levels More
Latest custom levels More
Latest adventures More
Latest puzzles More
mbz_clk500 commented on QuanTruckUm: 12 days ago
I love the advertising in this 😭mbz_clk500 commented on boykisser pixel art: 12 days ago
Goober :3Glados commented on Top Down Tank: 1 month ago
No, I mean, the thrusters only fire when they're in the 90° arch opposite to the heading direction, not using trigonometry to improve the thrust much moreBobMonkeypimp2 commented on Top Down Tank: 1 month ago
@Glados It's fully proportional to the angle just for some reason the body doesn't turn much. There's no stabiliser either.Glados commented on Top Down Tank: 1 month ago
Interesting, but I've seen that you only fire the thrusters in the 90° arch opposite to the heading direction instead of proportional to the angleowhame commented on haha, enjin go brrrrrrr: 1 month ago
Sorry😅But I really didn't have any choice😁
Galaxium commented on Spider Drone: 1 month ago
I likeGalaxium commented on haha, enjin go brrrrrrr: 1 month ago
"Sir, this is a wendys."