November 18, 2019

856 words 5 mins read



Web-based Cloud Gaming service for Retro Game

repo name giongto35/cloud-game
repo link
language Go
size (curr.) 174469 kB
stars (curr.) 764
created 2019-04-03
license Apache License 2.0


Open-source Cloud Gaming Service For Retro Games
Video demo:
My Slide at GopherconVN2019:


CloudRetro provides an open-source cloud gaming platform for retro games. It started as an experiment for testing cloud gaming performance with WebRTC and libretro, and now it aims to deliver the most modern and convenient gaming experience through the technology.

Theoretically, in cloud gaming, games are run on remote servers and media are streamed to the player optimally to ensure the most comfortable user interaction. It opens the ability to play any retro games on web-browser directly, which are fully compatible with multi-platform like Desktop, Android, IOS. It enhances crowdplay (TwitchPlaysPokemon) with realtime interaction. E.g: Play Pokemon Emerald together.

Try the service at

Single play:
Crowd play: Pokemon Emerald
Chrome and Chrome on Android is recommended. It’s not working on iPhone and some other explorers. Click help button in the game UI to see keyboard mapping.

*In ideal network condition and less resource contention on servers, the game will run smoothly as in the video demo. Because I only hosted the platform on limited servers in US East, US West, Eu, Singapore, you may experience some latency issues + connection problem. You can try hosting the service following the instruction the next section to have a better sense of performance.

Screenshot Screenshot
screenshot screenshot
screenshot screenshot


  1. Cloud gaming: Game logic and storage is hosted on cloud service. It reduces the cumbersome of game initialization. Images and audio are streamed to user in the most optimal way using advanced encoding technology.
  2. Cross-platform compatibility: The game is run on web browser, the most universal built-in app. No console, plugin, external app or devices are needed. Chrome with the latest version and fully WebRTC support is recommended for the game.
  3. Emulator agnostic: The game can be played directly without any extra effort to set up the gaming emulator or platform.
  4. Collaborate gameplay: Follow the idea of crowdplay(TwitchPlaysPokemon), multiple players can play the same game together by addressing the same deeplink. The game experience is powered by cloud-gaming, so the game is much smoother. Check CrowdPlay section
  5. Online multiplayer: The first time in history, you can play multiplayer on Retro games online. You can try Samurai Showndown with 2 players for fighting game example.
  6. Horizontally scaled: The infrastructure is designed to be able to scale under high traffic by adding more instances.
  7. Cloud storage: Game state is storing on online storage, so you can come back and continue playing your incomplete game later.

Run on local by Docker

You try running the server directly by make It will spawn a docker environment and you can access the service on localhost:8000.

Development environment

Install Golang . Because the project uses GoModule, so it requires Go1.11 version.

(Window only) Extra setup

Setup MSYS2 (MinGW) environment if you are using Windows:

  • Please refer to the Libretro doc for initial environment setup
  • Add Golang installation path into your .bashrc
    $ echo 'export PATH=/c/Go/bin:$PATH' >> ~/.bashrc
  • Install dependencies as described down bellow
  • Copy required Libretro Core DLLs into the cloud-game\assets\emulator\libretro\cores folder and replace existing Linux SOs in the cloud-game\pkg\config\config.go EmulatorConfig object.
  • Use C:\msys64\mingw64.exe for building
  • To run the app use either MinGw terminal or copy: libdl.dll, libogg-0.dll, libopenal-1.dll, libopus-0.dll, libopusfile-0.dll, libvpx-1.dll files from C:\msys64\mingw64\bin into the ./bin folder and then run.

(All) Install Dependencies

# Ubuntu
apt-get install -y pkg-config libvpx-dev libopus-dev libopusfile-dev

# MacOS
brew install libvpx pkg-config opus opusfile

# Windows (MSYS2)
pacman -S --noconfirm --needed git make mingw-w64-x86_64-toolchain mingw-w64-x86_64-pkg-config mingw-w64-x86_64-dlfcn mingw-w64-x86_64-libvpx mingw-w64-x86_64-opusfile

Because the coordinator and workers need to run simultaneously. Workers connect to the coordinator.

  1. Script
  • make
  • The scripts spawns 2 processes one in the background and one in foreground
  1. Manual
  • Need to run coordinator and worker separately in two session
  • go run cmd/overlord/main.go - spawn coordinator
  • go run cmd/overworker/main.go --overlordhost localhost:8000 - spawn workers connecting to coordinator



Crowd Play, play game together

By clicking these deep link, you can join the game directly and play it together with other people.

And you can host the new game by yourself by accessing and click “share” button to generate a deeplink to your current game.
Disclaimer: You may experience lagging when joining a room because the room is in a different zone. In that case, you should create a new room for crowd play.



  • The project cannot be possible without the contribution with those amazing people:
  • sergystepanov for Front end refactor; Audio re-implementation; bilinear, nearest neighbor interpolation scaling; Window setup document.
  • sadlil for massive code structure reogranization; log and monitor server introduction.



Nguyen Huu Thanh

Tri Dang Minh

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