I built this. 🔵 320 tiny spheres, falling, colliding and piling up exactly the way real beads would — running on a chip smaller than a coin. It’s an ESP32-S3 with a 2.06” AMOLED and a 6-axis IMU. The sensor reads the actual direction of gravity, so when I tilt the device the spheres don’t play a canned animation — they genuinely fall. What I wrote: → Verlet integration for the motion, so the spheres carry real momentum instead of just sliding. → A spatial hash grid for the collisions. Checking every sphere against every other one would mean 50,000 tests per frame; splitting the screen into cells cuts it to a few hundred. → No UI framework. Every sphere is a sprite I generate at boot — directional lighting, specular highlight, blue rim glow — and blit by hand into a framebuffer. Graphics libraries choke well before you hit 300 objects. I used Claude as my pair programmer: I described what I wanted, we argued about the bottlenecks, and it caught the mistake that was quietly halving...