Building your game

Write your game's code in C#, with a Visual Studio solution the editor generates for you.

Generate the project

Save your project first, then choose Build › Generate Game Project...

The Generate Game Project window, with C# selected

A project's sources can be written in either C# or C++. This page covers C#; switch to C++ at the top of the page.

To switch after selection, use Build › Change Language.... You can only change this when there are no changed files after generating the project.

Generate adds these to your project folder:

Projects/MyGame/
  MyGame.hypproject
  MyGame.slnx
  Source/
    MyGame.csproj
    MyGameGame.cs
    Program.cs
    Hyperion.Local.props

Your Game class

The generated class overrides three hooks from Game:

Method	When it's called
OnLaunch	Once, after the startup world has loaded.
OnUpdate	Every frame, with the time since the last frame.
OnShutdown	When the game shuts down, before the world is torn down.

The editor finds your class by name. Keep it named after your project with Game on the end (MyGameGame for MyGame.hypproject).

MyGameGame.cs open in Visual Studio

Build

Build from either place:

In Visual Studio, Build › Build Solution (Ctrl+Shift+B).
In the editor, Build › Build Game. Compiler output goes to the Console.

Both need the .NET 10 SDK. The result lands in your project's Binaries folder, next to a copy of the engine:

Projects/MyGame/
  Binaries/Windows/
    MyGame.exe
    MyGame.dll
    hyperion.dll
    Config/

MyGame.exe runs the game on its own, loading content straight from the project folder. It takes the same command line as a C++ game; see Run it.

Play it in the editor

Press Play. The editor loads MyGame.dll and runs your Game class in play-in-editor.

The example running in the editor: cubes circling the player

There's no hot reload for the game project. The editor keeps using the build it first loaded, so after rebuilding, restart the editor to see your changes.

Package

Build › Package Game works the same as for C++. The build includes the .NET runtime, so the packaged game runs on a machine without .NET installed. See Packaging a build.