Getting Started

What you need, the shortest path from empty folders to a running game, and where to go next.

To play, download a release (Releases: Windows, Linux, Android and the web). To build Galaxy Eggbert from source, you check out the game and the libraries it is built on side by side, configure it with CMake and run the result from its build directory. Linux is the verified desktop platform (as of 2026-11-12); the web, Android and Windows builds are covered in the Build Guide and their status in Platform Support.

Toolchain

Repositories

The game is compiled against CNA (a C++ reimplementation of the XNA 4.0 API) and cna-engine (its helper modules) as source, through add_subdirectory. CNA in turn needs three more checkouts. All of them sit next to galaxy-eggbert in one parent folder:

any-folder/
├── galaxy-eggbert/     the game
├── cna/                CNA (github.com/libcna/cna)
├── cna-engine/         helper modules (github.com/libcna/cna-engine)
├── easy-gl/            CNA's GL layer (github.com/libcna/easy-gl)
├── meta-gl/            needed by easy-gl (github.com/libcna/meta-gl)
├── sharp-runtime/      CNA's .NET-style runtime (github.com/libcna/sharp-runtime)
└── mobile-eggbert/     optional: only its worlds/ folder, for two tests

Other locations are possible: -DCNA_HOME=<path> and -DCNA_ENGINE_HOME=<path> point the game at CNA and cna-engine elsewhere (Configuration). The exact revisions CI builds against are pinned in .github/workflows/cna-ci.yml; when the newest CNA does not build, use those.

System packages

On Debian or Ubuntu these are the packages the CI job installs (SDL's audio, X11, Wayland and input back ends, the GL headers, FFmpeg for music, and libcurl/nlohmann-json for CNA's networking modules):

sudo apt-get install -y --no-install-recommends \
  build-essential ninja-build pkg-config ccache \
  libasound2-dev libpulse-dev libaudio-dev libfribidi-dev libjack-dev \
  libsndio-dev libx11-dev libxext-dev libxrandr-dev libxcursor-dev \
  libxfixes-dev libxi-dev libxss-dev libxtst-dev libxkbcommon-dev \
  libdrm-dev libgbm-dev libgl1-mesa-dev libgles2-mesa-dev \
  libegl1-mesa-dev libdbus-1-dev libibus-1.0-dev libudev-dev \
  libthai-dev libwayland-dev wayland-protocols libdecor-0-dev \
  libavcodec-dev libavformat-dev libavutil-dev libswresample-dev \
  libcurl4-openssl-dev nlohmann-json3-dev

Optional: xvfb-run (headless runs and the demo-replay test), Python 3 with numpy and Pillow (asset tools), the Emscripten SDK (web build), Android Studio with SDK 35, NDK 29.0.14206865 and JDK 17 or 21 (Android build).

The shortest path to a running game (Linux)

mkdir eggbert && cd eggbert
git clone https://github.com/openeggbert/galaxy-eggbert.git
git clone https://github.com/libcna/cna.git
git -C cna submodule update --init          # SDL3, SDL3_mixer, ... (not recursive)
git clone https://github.com/libcna/cna-engine.git
git clone https://github.com/libcna/easy-gl.git
git clone https://github.com/libcna/meta-gl.git
git clone https://github.com/libcna/sharp-runtime.git

cd galaxy-eggbert
cmake -S . -B build-cna-opengl3 -G Ninja \
  -DCMAKE_BUILD_TYPE=Release -DCNA_GRAPHICS_RENDERER=OPENGL33
cmake --build build-cna-opengl3 --target GalaxyEggbertCNA --parallel 4

cd build-cna-opengl3
./GalaxyEggbert

• The CMake target is GalaxyEggbertCNA; the file it produces is GalaxyEggbert (GalaxyEggbert.exe on Windows, GalaxyEggbert.html on the web).
• OPENGL33 is the renderer the maintainer plays with. Leave the option out and you get the project's native default, OPENGLES3; both are verified on Linux.
• Run the game from its build directory: it reads Content/, worlds3d/, textures3d/ and avatars3d/ by relative paths, and a post-build step copies them there. Running the Game explains why and lists every command-line flag.

On the first start the game prints where it keeps your files, for example GalaxyEggbertCNA: the player's files are in /home/you/.local/share/Galaxy Eggbert: settings and progress (savedata.txt), an interrupted mission (resume.txt), your demo recordings (demos/) and your own worlds (customworlds/).

Your first minutes in the game

• F1 shows the controls; Esc pauses; F11 switches between window and full screen (the first run is windowed; the choice is remembered).
• Walk with WASD or the arrows, jump with Left Ctrl, act with Space. Gamepads are supported (checked with SDL's virtual gamepad; no physical pad has been tried yet). All bindings are on Controls.
• The main menu's Setup holds the sound, the 3D effects (Off to Ultra), the frame rate and the textures (Configuration, 3D Effects & Graphics).

Checking the build

To run the test suite, build every target (the tests are separate executables) and run ctest. Clone mobile-eggbert first, or two tests fail:

cmake --build build-cna-opengl3 --parallel 4
ctest --test-dir build-cna-opengl3 --output-on-failure

All tests pass on the maintained tree (120 of 120 on 2026-11-10). Details in the Build Guide and Testing.

Where to go next