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

Top rated levels More

Latest custom levels More

Latest adventures More

Want more? Check out the Official community site archive, a complete archive of levels spanning 2013 to 2018

Latest comments

MDJappas commented on Plank: 3 days ago

Wow

jacobsladder55 commented on He never got over it..: 4 days ago

This is just as infuriating as the real deal. Damn.

jacobsladder55 commented on Air Plane: 5 days ago

Fun

sd95 commented on Air Plane: 7 days ago

Plane crashed like 9/11

sd95 commented on MAZ 537G: 7 days ago

Throttle not working. It falls down by itself.

Galaxium commented on Rocket Thingy (Warning: Very Technical): 7 days ago

All the easy and mediocre ideas are already taken, leaving only the harder and more obscure ideas :( so ig it makes sense

MEMORY_LOST commented on Tank Suspension Track (Prototype): 8 days ago

that main gear to drive the tracks is brilliant!, it graps the chains very well, delivering a smooth force/ride not slippy or skipping like other designs.
i honestly don't know why i haven't thought about that design.

Ropster commented on Interesting car game with leaderboard: 12 days ago

Interesting