Mastermind

A code-breaking game with a "Cyberdeck Terminal" neon-HUD interface, built as a Lakebed capsule. Crack a server-generated secret code; feedback is per position — under each peg a mark shows exact (◉), shifted (◐), or absent (○).

Features

• Four difficulty modes — Easy (5 pegs) → Normal (6) → Hard (7 unique) → Insane (8 unique), all 10 tries. Switching applies to your next game, never resetting the shared one in progress.
• Candidate-space helper — counts how many codes still match your guesses (client-side deduction; the secret never leaves the server).
• Telemetry — per-difficulty win rate, crack-distribution histogram, and streaks.
• Live activity feed — recent finished games across all players (a real server query).
• Signal-lock meter, colour-blind symbol mode, keyboard controls, confetti on win, and a 5-second cooldown between guesses.

Why it's interesting

The secret code is generated and scored entirely server-side and is stored in the capsule database. The currentGame query withholds the secret while a game is in progress — it's only revealed once you win or run out of guesses — so it never reaches the browser and can't be read from the client. Every guess is validated and scored on the server. Each player (guest or Google-authenticated) gets their own game.

Tech

• Lakebed capsule — full-stack TypeScript, server contract + Preact client.
• server/index.ts — games and guesses tables, currentGame/guesses queries, newGame/submitGuess mutations.
• client/index.tsx — Preact UI, Tailwind classes inline.
• shared/mastermind.ts — pure game logic (scoreGuess, validation, constants).

Run locally

npx lakebed dev

Open http://localhost:3000. Add ?lakebed_guest=alice to play as a named guest.

Inspect local state while lakebed dev is running:

npx lakebed db dump --port 3000    # see games (incl. secret) and guesses
npx lakebed logs --port 3000

Deploy

Deploys anonymously (no claim needed) — the game is fully self-contained with no outbound network calls:

npx lakebed deploy