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Build retro games using WebAssembly for a fantasy console


WASM-4 is a low-level fantasy game console for building small games with WebAssembly. Game cartridges (ROMs) are small, self-contained .wasm files that can be built with any programming language that compiles to WebAssembly.

Key Features

  • No Glue Code: If you've ever tried to write even a simple "Hello World" with WebAssembly before, you'll know it usually involves writing a bunch of JS and HTML glue. WASM-4 removes all of that, games interface directly with the system through a small API.

  • Minimalist: Fantasy consoles force developers to work with limited resources. This makes them simple to learn, and easier to focus on finishing your game.

  • Language Agnostic: Use any programming language, as long as it can compile to WebAssembly. Out of the box we currently support: AssemblyScript, C/C++, D, Go, Nelua, Nim, Odin, Rust, WAT, and Zig.

  • Portable: WASM-4 is designed to run on any device that can execute WebAssembly, even outside of the web! It includes a lightweight runtime written in C that runs even low-powered microcontrollers and obsolete hardware.

  • Netplay: Instant online multiplayer, featuring rollback netcode. All games that support local multiplayer automatically support netplay. WASM-4 handles syncing controller inputs over the Internet.

🚀 60 Second Quickstart

# Install the w4 command
npm install -g wasm4

# Create a project
w4 new --assemblyscript hello-world

# Setup toolchain
cd hello-world
npm install

# Build and run your game!
npm run build
w4 run build/cart.wasm

For more info and guides, check the full documentation.

🎮 Hardware Specs

  • Display: 160x160 pixels, 4 customizable colors, updated at 60 Hz.
  • Memory: 64 KB linear RAM, memory-mapped I/O, save states.
  • Cartridge Size Limit: 64 KB.
  • Input: Keyboard, mouse, touchscreen, up to 4 gamepads.
  • Audio: 2 pulse wave channels, 1 triangle wave channel, 1 noise channel.
  • Disk Storage: 1024 bytes.

🙏 Contributing

Contributions are welcome! Here are just a few ways to help:

  • Build a game or experiment, we'll feature it on!
  • Improve our documentation or write a tutorial.
  • Submit a bug report or feature request on Github.
  • Answer questions on the discussions forum.
  • Implement support for a new tool or language.
  • Give the project a star on Github for visibility.