Inspiration

classic falling-sand games like Powder Game
user-generated content platforms like Super Mario Maker
bringing creative physics toys to Reddit communities

What it does

A falling-sand physics simulator where users paint with 18+ materials (sand, water, fire, lava, plants, etc.) and watch them interact in real-time. Users can share their creations as Reddit posts, and anyone can load those builds, modify them, and share their own versions—creating a chain of community remixes.

Users get to experiment with physics, create art, and build upon each other's work, all natively on Reddit.

How we built it

Devvit Web, Rust/WASM for physics simulation, React

Challenges we ran into

Getting smooth 60fps physics simulation in WebAssembly while keeping the bundle size small for Reddit's platform was tricky. Also implementing the build sharing system so users could seamlessly load and remix each other's creations.

Accomplishments that we're proud of

Creating a full physics sandbox with 18 interactive materials and a complete sharing system in a short time. The remix feature where users can build on each other's work turned out really well!