Show HN: An interactive physics simulator with 1000's of balls, in your terminal

Summary

ballin Crates.io A colorful interactive physics simulator with thousands of balls, but in your terminal! ballin is a fun TUI app written in Rust that simulates thousands of logical balls, but despite the inherent character constraints of a terminal, you can see the realistic physics of the balls in action: Extremely high performance using the rapier 2D Rust physics engine: it can handle physics actions on 10,000 balls at effective 120+ FPS! 2D Rust physics engine: it can handle physics actions on 10,000 balls at effective 120+ FPS! Uses Braille Unicode to allow visualizing small, discrete balls. Clicking the balls to cause a repulsing burst, or by using the geysers by pressing 1-6 or clicking them. or clicking them. Clicking the top area of the canvas spawns more balls: clicking-and-holding spawns many balls. Shake the entire canvas by resizing the terminal vertically, or by pressing the arrow keys to perform a pinball tilt. Change the amount of gravity, friction, and the force of interactive effects to generate some very wacky interactions! Add shape objects to obstruct the balls and create your own physics gym. You can even change the colors of the shapes to make it beautiful! Save your constructed physics environment as a sharable JSON file! Watch the color explosion in action! ballin.mp4 Disclosure: This crate was developed with the assistance of Claude Opus 4.5 initially to answer the shower thought "would the Braille Unicode trick work to visually simulate complex ball physics in a terminal?" Opus 4.5 one-shot the problem, so I decided to further experiment to make it more fun and colorful. The full list of prompts used with Claude Code is present in PROMPTS.md. Installation The app binaries can be downloaded from the Releases page for your platform of choice, or by using the following terminal commands: # macOS Apple Silicon curl -sL https://github.com/minimaxir/ballin/releases/latest/download/ballin-macos-arm.tar.gz | tar xz # macOS Intel curl -sL https://gi...