PokéHealth

A mashup of Pokémon Red and Apple HealthKit. What you did yesterday affects how the game plays today.

Your steps, sleep, calories burned, and workout minutes from the previous day feed into the game as modifiers. Walked 15k steps? Your character sprints across Kanto. Slept well? Pokémon Centers fully heal your team. Had a good workout? You earn more money, catch Pokémon more easily, and gain XP faster. Stayed on the couch? The game quietly pushes back.

It runs entirely in the browser as a PWA — a patched Pokémon Red ROM inside a Game Boy emulator compiled to WebAssembly, with health data pulled from HealthKit via pwa-kit. No server. No account. Everything local.

How it works

Each day, your health stats map to gameplay modifiers — movement speed, healing quality, XP rate, money earned, and catch rate. The game reads these on every frame and adjusts accordingly. You can inspect your active modifiers from the in-game START → HEALTH menu.

See docs/modifiers.md for the full tier tables, and docs/architecture.md for the technical deep dive into ROM patching, the hook protocol, and emulator integration.

Setup

Prerequisites

• Bun — runtime and package manager
• rgbds — Game Boy assembler/linker (brew install rgbds on macOS)
• Emscripten — WASM compiler (emsdk)

Note: Emscripten must be on your PATH. If you installed via emsdk, run source <emsdk-dir>/emsdk_env.sh first (or add it to your shell profile).

Getting started

# 1. Clone with submodules (pokered + binjgb)
git clone --recursive <repo-url>
cd pokehealth

# 2. Install JS dependencies
bun install

# 3. Build the binjgb WASM emulator (~60s first time, ~2s incremental)
bun run emu:build

# 4. Build the patched Pokémon Red ROM (~30s first time, ~5s incremental)
bun run rom:build

# 5. Start the dev server
bun run dev

Open http://localhost:5173. The game auto-boots into Red's room. Use the Debug tab to set health values and Apply them to the running game. Open the in-game START → HEALTH menu to verify.

Already cloned without --recursive? Run git submodule update --init --recursive to fetch the submodules.

Deploy

bun run ship    # build everything + deploy to Cloudflare Workers

iOS app

The native iOS wrapper is built with pwa-kit, which provides the HealthKit bridge. To configure a fresh clone:

npx @pwa-kit/cli init ios --url "https://pokehealth.eddmann.workers.dev/" --features "healthkit"

Then open the generated Xcode project in ios/, and build to a device or simulator.

Disclaimer

This project does not distribute any Nintendo-copyrighted content. The Pokémon Red ROM is built locally from the pret/pokered disassembly — you must build it yourself with bun run rom:build. Pokémon is a trademark of Nintendo / Game Freak / Creatures Inc. This is a fan project with no commercial intent.

The binjgb emulator is used under the MIT License.

Project structure

pokehealth/
├── rom/
│   ├── pokered/              # git submodule (pret/pokered, unmodified)
│   └── patches/
│       ├── apply.sh          # Patch application script
│       └── health_menu.asm   # In-game HEALTH screen (assembly)
├── emulator/
│   └── binjgb/               # git submodule (binji/binjgb)
├── scripts/
│   ├── build-rom.sh          # Patch + build ROM → public/roms/
│   └── build-emu.sh          # Build binjgb WASM → public/wasm/
├── src/
│   ├── lib/                  # Emulator wrapper, hooks, health tiers, DB, cheats
│   ├── stores/               # React context for health state
│   ├── hooks/                # useEmulator, useHealthKit
│   └── components/           # GameScreen, DebugScreen, TouchControls, SaveLoad, Nav
└── docs/
    ├── modifiers.md          # Health inputs and gameplay modifier tier tables
    └── architecture.md       # ROM patching, hook protocol, emulator, PWA details