# Crystal

A native web port of Pokémon Crystal, translated from [PRET's Game Boy disassembly](https://github.com/pret/pokecrystal). The game runs in TypeScript and reads graphics, maps, sprites and dialogue from the user's own ROM. No original game assets are included.

**Current milestone: from the opening to Route 30.** Play in a minimal Crystal-style interface with Game, Savegames, Map, Pokédex, Link and Friends tabs. The native canvas fills the play area, and the live local map follows your position. Save, export and import work now. Pokédex, Link and Friends show their planned scope without placeholder data.

Walk around your home, the town and its buildings at the original walking speed. Mom gives you the Pokégear and asks the day of the week. The teacher stops you from leaving town. Your rival shoves you away from the lab window. Professor Elm introduces his errand, and you choose Chikorita, Cyndaquil or Totodile. The Pokémon's picture and stats come from your ROM, and you can nickname it. Elm's aide then gives you a Potion. These scenes run the game's own event scripts and movement data, with native choices and naming.

With a Pokémon, head west along Route 29 to Cherrygrove City. Wild Pokémon appear in the grass and battle you with their original moves. The route has ledges, signs, an item ball and a Berry tree that regrows daily. Townspeople wander and look around as in the original. In Cherrygrove, the Guide Gent gives a tour, the Poké Mart buys and sells items, the Pokémon Center nurse heals your party, and a whiteout returns you to the last Pokémon Center you entered.

North of Cherrygrove, Route 30's trainers battle you. Bug Catcher Don spots you from a distance and walks over; Youngster Mikey battles when you talk to him. Each sends out two Pokémon, and beaten trainers remember you. The Berry house gives a Berry, and a Potion is hidden on the route.

Mr. Pokémon gives you the Mystery Egg, and Professor Oak gives you the Pokédex. Your rival challenges you in Cherrygrove on the way back, and Elm's aide gives you Poké Balls. Back on Route 29, the Dude shows you how to catch Pokémon. From then on, open PACK in a wild battle to throw a Poké Ball. Caught Pokémon join your party, and you can give them a nickname. In battle, PKMN switches Pokémon or opens a Pokémon's stats, and when one faints you choose the next. PACK's Items pocket uses healing items, revives, Ethers, X items and Poké Dolls.

Start opens the start menu. POKéMON shows your party: open a Pokémon's stats, change the order, rearrange its moves, or give and take held items. PACK shows your pockets: use Potions, status healers, revives, Ethers, PP Ups, vitamins, Rare Candy and evolution stones, give or toss items, and ride the Bicycle. Pokémon evolve when they level up after a won battle (press B during the flashes to stop it), and learn new moves outside battle too. Select opens Key Items, including the Bicycle when owned. The poster opens the Town Map.

The Pokémon Center PC opens Bill's PC, your own PC and, once you have the Pokédex, Professor Oak's rating. Deposit, withdraw and release Pokémon, and switch or name boxes. Store, withdraw or toss items. With six Pokémon in your party, a catch goes to the current box. When that box fills up, Bill calls you. The bedroom PC also lets you arrange owned decorations.

Route 31 and beyond, trade evolutions, the Pokégear, Pokédex and trainer card screens, field moves from the menu, MAIL, moving Pokémon between boxes, Kurt's special balls and audio are still being ported. Unported neighboring areas appear at the edges but cannot be entered yet.

## Run

Requires Node.js 22.12 or newer.

```sh
npm ci
npm run dev
```

Open the printed local URL and select your uncompressed **English US/Europe revision 1.1** ROM (`.gbc`, 2 MiB). Its checksum is verified locally. ROMs are never uploaded or stored in browser storage; select yours again after reloading to resume. A new game starts with Professor Oak's introduction, where you choose your character, set the clock and pick a name.

Use onscreen controls, or focus the game screen and use arrows to move, **X** to interact and **X / Z** to continue dialogue. In choices, **Up / Down** change the answer, **X** confirms and **Z** answers No. Sessions save every 10 seconds and when paused. Switching apps pauses play. Download a backup before clearing browser data.

Native saves are separate from emulator snapshots and cartridge `.sav` files. Saving during a scene keeps the progress from before it, so the scene replays after loading. The time you give Oak is kept as an offset from the device clock (the steppers start at the device's time), and the weekday you give Mom as an offset from that clock's weekday. The tile counter measures in-game movement, not real-world steps.

## Reference emulator

During development, open **`/reference.html`** to run the original game for comparison. It has separate saves and does not run inside the native player. Reference tools and the emulator are excluded from the default build.

```sh
npm run build             # Native application in dist/
npm run check:release     # Check the native distribution
npm run build:reference   # Optional reference in dist-reference/
```

Serve `dist/` through an HTTPS static host, or use `npm run preview` locally. Subdirectory hosting is supported with `npm run build -- --base=/Crystal/`. Use HTTPS from another device; ROM verification and save locking require a secure context.

## Development

```sh
npm test
npx playwright install chromium webkit
npm run test:e2e
npm run check:vendor
```

Local-ROM tests use `Pokemon - Crystal Version (UE) (V1.1) [C][!].gbc` at the root, or `CRYSTAL_ROM_PATH`. They skip when absent; no test downloads a ROM. Game files, private reference builds and gameplay screenshots must remain ignored.

The [full port plan](docs/PLAN.md) covers remaining game systems, save slots, the world map, Pokédex, internet Link, friends and optional mobile step support for egg hatching. See the [architecture](docs/ARCHITECTURE.md) and [routine map and verification](docs/NATIVE_PORT.md) for module boundaries and reference checks.

References: PRET [documentation](https://pret.github.io/pokecrystal/), [wiki](https://github.com/pret/pokecrystal/wiki) and [source](https://github.com/pret/pokecrystal). The development reference uses [binjgb](https://github.com/binji/binjgb) under its [MIT license](reference/public/vendor/binjgb/LICENSE); see [provenance](reference/public/vendor/binjgb/PROVENANCE.md).

Independent project. Not affiliated with Nintendo or Game Freak.