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By Bithack

This app is only available on the App Store for iOS devices.


Welcome to the world of Principia.
Solve puzzles using the laws of physics. Help the robot get to the goal by building contraptions, bridges and vehicles.

Open up the sandbox editor and use over 190 unique objects to create anything from a simple teeter totter to a working calculator. Use the advanced electronics system to create your own games. Upload your creations to the community website or download creations by others.
Join thousands of other players and compete in the weekly Building Contests!

Play freely in the Adventure mode, explore worlds and progress by gathering resources and constructing objects that can be used to build anything you can imagine.

What's New in Version

Fixed a few critical graphics glitches occurring on newer iOS devices (iPhone 5S, iPad Air), and some crashes related to dialogs.
Improved opening/closing of community view.
Added more links to help resources.


iPhone Screenshot 1
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iPad Screenshot 1
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Customer Reviews

Horrible tutorial makes it hard to play

This game looks really fun, but I may end up quitting before I find out how much fun it is. Their tutorial is a joke. Instead of being an in-game tutorial to teach you what you're supposed to do (and there's quite a bit to do that you wouldn't figure out on your own), they have their tutorial as a pop-up almost like a text message. That reminds me of the first apps that came out years ago. The stupid pop-up says "See those something or other over there?" Umm, nope, your stupid pop-up is blocking the screen. And the instructions are a few paragraphs which I happened to forget a bit of. So in the game I hit the question mark for help and a stupid pop-up says to use the instructions that they've given you. So you need to have a stellar memory to even remember everything they throw at you because you can't go back to the instructions. For now this is two stars because it looks fun. I'll happily up the rating if I end up caring enough to give it another shot.


I like this app a lot, it has a heaping helping of the open creation aspect that I am always on the look out for. It also looks very nice (I would have liked some different textures and a slightly less messy look, like the very loose wires... but I am a picky art director).

I agree with some of the other reviewers that the tutorial and controls leave a something to be desired, especially since I am mainly interested in this type of app for my young son who tears through anything like this with abandon. I am afraid this app won't hold his attention however since he may not be given enough information on how to progress. I know what some of you are thinking... but young kids freakin LOVE this stuff and if you make it accessible to them they can accomplish a lot in an app like this, even on their own.

Still I can't wait to show it to him and see what he does with it.


Very well-made game. I really like the look of the graphics--it almost looks like stop-motion or like it was made using an actual little robot that stomps around.

View in iTunes
This app is designed for both iPhone and iPad
  • $3.99
  • Category: Games
  • Updated:
  • Version:
  • Size: 20.4 MB
  • Language: English
  • Seller:
Rated 12+ for the following:
  • Infrequent/Mild Simulated Gambling
  • Frequent/Intense Cartoon or Fantasy Violence

Compatibility: Requires iOS 6.0 or later. Compatible with iPhone, iPad, and iPod touch.

Customer Ratings

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