GitHub - btahir/stillplay: Minesweeper, FreeCell, Solitaire, Spider and Hearts, rebuilt for the browser. C rules compiled to WebAssembly, offline, no installs, no accounts.

The games

Minesweeper Beginner, intermediate, expert. Your first click is always safe.	Solitaire Draw one or three, standard or Vegas scoring, and the bouncing cards when you win.	FreeCell Every numbered deal, including the famous #11982.
Spider Solitaire One, two or four suits. Finished runs lift away.	Hearts Three computer players who pass, duck and dump points like people do. Watch out for the queen.

What's in the box

• Real card handling. Drag a card or a run, tap to pick up and tap to drop, or double-click to send a card home. Moves animate. Illegal drops spring back.
• Plays by keyboard. Arrow keys between piles, Enter to pick up and put down, Ctrl/Cmd+Z to undo. Press ? on any game for its shortcuts.
• Sound you can feel. Felt, card and wood sounds, off until you turn them on. The sound file is only downloaded then.
• A daily for every game. The same board or deal for everyone, all day, with streaks.
• Your stats stay with you. Wins, best times and streaks are kept in your browser. There is no backend and nothing to sign up for.
• Two looks. Original pixels for the period feel, Crisp for sharp modern screens. Light and dark themes.
• Installable and offline. Add it to your home screen or dock. After the first visit it plays without a connection.
• Replays and share links. Every game is deterministic. Export a replay file, or share a link that replays your exact game.
• Phone-sized. Every game fits a 320 px screen and plays by touch.
• Fast. About 75 KB to a playable home page. Each game's code and rules load only when you open it. Lighthouse scores 100 in all four categories.

Play locally

Requires Node 24 and pnpm 11.

pnpm install --frozen-lockfile
pnpm dev --port 4179

Open localhost:4179. The home page boots straight into a game; the switcher above it changes which one.

How it's built

Everything is our own code. There is no framework and no bundler: plain HTML, CSS and ES modules.

• Rules in C, compiled to WebAssembly. Each game's rules live in cores/<game>.c, written without libc and compiled to a 4–15 KB WASM module. The same module runs in the browser and in Node, so a replay produces the same state in both.
• One shared card table. src/card-table.js handles drag and drop, tap and keyboard input, move and deal animations, and the win cascade for all four card games. Each game is a thin src/<game>-ui.js on top.
• A registry-driven site. src/games.js lists the collection. Routes, the home page, daily pages, metadata and the sitemap are generated from it. A game with a mount is playable; one without shows as coming soon.
• A static build. pnpm build prerenders every route, writes per-page metadata, JSON-LD and Open Graph images, compresses everything with Brotli and gzip, and generates the offline service worker.

cores/        C rules and the compiled .wasm modules
src/          game UIs, card table, card art, audio engine, replay format
src/site/     router, pages, game toolbar, stats, dialogs
scripts/      dev server, build, xpc CLI, browser tests, Lighthouse
tests/        unit and property tests for every core
docs/         core notes and the replay format

To rebuild the cores you need a Clang with the wasm32 target and wasm-ld, for example wasi-sdk. Put it on your PATH or set CLANG=/path/to/clang:

pnpm build
pnpm preview --port 4179

pnpm build --no-cores reuses the committed WASM. SITE_URL sets the absolute origin used in metadata (default https://stillplay.shiptiffin.app).

Headless play

The xpc CLI runs the same WASM cores in Node and prints JSON, which makes every game playable by scripts and agents.

pnpm xpc minesweeper new --level expert --seed 42 --json
pnpm xpc solitaire new --seed 7 --draw 3 --json
pnpm xpc solitaire hint --json
pnpm xpc spider new --suits 2 --seed 7
pnpm xpc hearts new --seed 3 && pnpm xpc hearts hint --json
pnpm xpc freecell deal 11982 --json
pnpm xpc replay export game.json

State is saved in .stillplay-state.json by default; pass --state FILE to keep separate games. Replays are versioned JSON with the game's settings and its ordered inputs. See docs/replay-format.md.

Tests

Browser tests, Lighthouse and the build's preview images use Playwright's headless Chromium. Install it once:

pnpm exec playwright install --only-shell chromium

pnpm test            # 60 unit and property tests
pnpm test:browser    # 41 browser scenarios in headless Chromium
pnpm lighthouse      # Lighthouse on the built site

The unit tests play thousands of seeded games per core: they check that cards are conserved and every move is legal, that replays round-trip, and that scoring is right. They also measure the Hearts players (96.7% wins against random play, about 25% each at a four-way table) and how often a simple solver wins one-suit Spider. The browser scenarios drive the real UI with mouse, keyboard and touch, from deal to win cascade, at desktop and 320 px sizes, and compare each game window against approved screenshots.

Credits

• Typefaces: DM Serif Display and Space Grotesk, both under the SIL Open Font License (licences in public/fonts/).
• Sounds: generated for this project with Mirelo SFX and mastered by hand, or synthesised. See public/audio/CREDITS.md.
• All game art, including the cards, is drawn in code. Stillplay ships no Microsoft bitmaps, icons, sounds or executables.

Licence

MIT. Stillplay is an independent fan project, not affiliated with or endorsed by Microsoft. "Windows XP" is used only to name the games it pays tribute to.