Principia

Principia is an open-source, physics-based sandbox building game for Android. It is intended for players who want to construct interactive machines, experiments, and games rather than follow only a fixed game format. Its building system supports creative play and hands-on exploration of how different parts behave together.

The sandbox offers more than 200 objects, including wooden building blocks, circuitry, and electrical and mechanical components. Players can use these parts to make contraptions such as controllable cars and calculators. Small robots can be controlled and fought, and robot-focused adventures are among the possible projects. A LuaScript object adds Lua scripting that can interact with the game world, allowing players to create systems or their own games through code as well as circuitry.

Principia also connects with a community site containing tens of thousands of levels made by players. These levels range from elaborate contraptions to amusing minigames and can be browsed and played as additional content. A level can be opened in the sandbox so its construction can be examined, making the community material useful as both playable content and examples for building.

As an Android title in the Games category, Principia fits devices where users can build and play within a single sandbox environment. MirrorNest distributes the official build directly from its own storage and scans it for malware before publishing. The open-source license reflects the community-developed nature of the project, while Android is one of the platforms on which Principia is available.