The Powder Toy is a physics "sandbox" game that simulates a variety of elements including air pressure, velocity, heat, gravity and a countless number of interactions between different "substances" drawn on to the 2D landscape. Included are a variety of different materials, liquids, gases and electronic components are available to construct complex machines (including catapults, guns and bombs) as well as realistic terrains and environments. You can then mine them and watch explosions, add intricate wirings, play with stickmen or operate your machine.

The program features a vibrant community of available saved worlds and creations and is built on a platform that welcomes automation and tweaking.

Cross-platform (Mac and Linux).