2010 - Present
The Powder Toy is a physics sandbox game, or sometimes called a "falling sand" game, where only your imagination is the limit.
The player can watch simple reactions of different materials interacting with each other, or create complex machines and electronic devices, landscapes, and infinitely more. It really is the ultimate sandbox, in a tiny package.
The game simulates particle physics, air pressure and velocity, heat physics, gravity, and many other forces. The player is given a huge variety of materials to build and create from - including solids, liquids, gasses, metals, electronics, explosives, atomic, and so much more. If users still find themselves to be limited to the wide selection of particle elements available, they can create their own particle types quickly with the built-in Lua scripting API.
The Powder Toy was, and still is, a very popular micro-game with a large and active community. Originally a closed-source game written in C pre-2010, the source code was given to another developer to expand the game and license it as open-source, and the game has been completely overhauled since. I was one of only a small handful of developers to help transition the game from a closed-source state into the open-source community. Not too long afterwards, our team has completely rewritten the game from C to C++ in an object-oriented and modular format to allow easier modability, and now has an entire community of contributors.
The game is still actively being developed by the open-source community and has expanded from a simple and addictive toy into a massive sandbox.