The idea started as a joke: what if CAPTCHAs were actually fun? Then I realized the core mechanic (solve a visual puzzle under time pressure) is basically a competitive game waiting to happen. The interesting technical challenge was making it cheat-proof. The CAPTCHA engine is Rust compiled to WASM. The server never sends images, just a seed number. Both the client and server independently generate the identical CAPTCHA from that seed, so there is nothing to intercept. Answers are validated server-side by the same WASM module running inside Cloudflare Durable Objects. There are 12 CAPTCHA types across 4 tiers. Tier 1 is what you would expect: distorted text, math, image grids. By Tier 4 things get weird: CAPTCHAs that animate and morph while you are trying to solve them, typography deliberately designed to fool OCR but stay human-readable, and multi-step chains where each correct answer reduces your time for the next one. I wrote up the full architecture and design decisions here: https://sean-reid.github.io/blog... Would love to hear which CAPTCHA types people find hardest, and any ideas for new ones. The generator system is modular so adding new types is straightforward.

CAPTCHA Royale

Race to solve CAPTCHAs, last player standing wins

Race to solve CAPTCHAs, last player standing wins