The Powder Toy is a free physics sandbox game for desktop and other platforms, built around the classic falling-sand concept. It simulates air pressure and velocity, heat, and gravity, allowing players to explore how different materials interact. The game offers a wide range of building materials, liquids, gases, and electronic components for creating landscapes, cities, machines, guns, and explosives. Players can experiment with their creations, mine materials, trigger reactions, operate machinery, and play with stickmen. The experience combines open-ended construction with playful destruction, while inviting curiosity about everything from complex circuits to power plants.

A community library lets players browse and play thousands of shared creations, as well as upload their own. The game also includes a Lua API for automation and plugins, giving technically minded players ways to extend their experiments. The Powder Toy is available for Windows, macOS, Linux, Android, and through Steam, with older versions and snapshots also offered.