67Ranked

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  67Ranked

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  in game

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  home page

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  mode select

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  6-7 duels

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  end screen

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  solo mode share card

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  duels share card

Inspiration

Everyone’s a little brainrotted now. Infinite scroll, zero patience, constant stimulation. We wanted to build something that embraces that reality instead of fighting it.
67Ranked turns short attention spans into a shared, physical, competitive experience that anyone can jump into instantly.

What it does

67Ranked is a camera-based web game where your body is the controller.
Players compete to complete fast “67” hand-movement reps across multiple modes, submit their score or time, and instantly see how they rank on a global leaderboard.
No accounts, no downloads, no instructions, just start 67ing. You can share your score with friends to challenge them to beat you, but best of all...

67 DUELS: duel your friend to see who can 6 more 7s in any of our gamemodes!

How I built it

• Frontend: Next.js, React, TypeScript, TailwindCSS
  
• Computer Vision: MediaPipe Pose for real-time wrist tracking
  
• Rep Detection: Velocity-based peak and valley detection on wrist positions
  
• Backend: Next.js API routes + Supabase Postgres
  
• Security: JWT-based game sessions to prevent fake score submissions, custom rate limiting, custom profanity filter
• Hosting: Vercel
  

All processing happens on-device for speed and privacy, with only validated scores sent to the backend.

Challenges I ran into

• Tracking very fast hand movements without losing accuracy
  
• Preventing false reps caused by jitter or brief tracking loss
  
• Designing cheat resistance without adding friction to gameplay
  
• Balancing responsiveness with stability for sub-second interactions

Accomplishments that I'm proud of

• Built a real-time, camera-powered game that works on both mobile and desktop
  
• Achieved reliable rep counting even at very high speeds
  
• Shipped a global leaderboard with anti-cheat protections
  
• Created a polished, shareable score experience with dynamic OG cards
  
• Delivered a complete, end-to-end product rather than a prototype

What I learned

• Larger, more stable landmarks outperform detailed ones in high-speed motion
  
• Designing for real user behavior leads to better products
  
• Anti-cheat systems can be invisible if integrated early
  
• Strong constraints lead to clearer, more focused design decisions

What’s next for 67Ranked

• Friend-based and regional leaderboards
  
• New movement patterns and limited-time modes
  
• Enhanced visual feedback tied to speed and rhythm
  
• Expanding into a platform of ultra-fast, body-controlled games

Built With

• css
• mediapipe
• next.js
• react
• supabase
• tailwind
• typescript