# Port a Unity game by rebuilding it, with your C# as the spec > No engine imports a Unity project. Porting a Unity game means rebuilding a project you own, using your existing C# and assets as the source material. - URL: https://www.summerengine.com/port-a-unity-game - Keyword: port a unity game - Related: https://www.summerengine.com/porting Porting a Unity game means rebuilding a project you own in another engine. There is no importer that reads a Unity project and produces a working equivalent. Anyone claiming otherwise is describing an asset copy, not a port. Scenes, prefabs, components, physics settings, and animator graphs are Unity specific formats. What you keep is substantial. Your art and audio source files are standard formats and import directly. Your C# gameplay code is a precise specification of your systems, and C# is available in the Summer Engine desktop editor. Your design, tuning values, and level layouts all transfer as data. One caution on assets. Unity Asset Store licensing generally permits use inside Unity projects, so third party packages usually cannot move with you. Your own art, your own code, and assets licensed without engine restrictions are the ones you can take. Summer Engine is compatible with Godot 4 workflows, is a fully custom engine with more than a million lines of custom code, and charges no royalties. ## How Unity concepts map to a scene tree A GameObject with components becomes a node with children and a script. A prefab becomes a reusable scene you instance. MonoBehaviour Update becomes a per frame process callback, FixedUpdate becomes a physics process callback, and Awake and Start become ready and initialization. Rigidbody and Collider become physics bodies and collision shapes. Coroutines become async functions or timers. ScriptableObjects become resource files. The mental model is close enough that most developers are productive within a day. ## C# moves, with one platform limit Summer Engine runs C++, GDScript, and C#, and C# is available in the desktop editor. That matters when you choose your rebuild language. Keeping gameplay in C# is the shortest path from Unity, while GDScript is the language most Godot 4 examples and tutorials use. Your original C# remains useful either way as the authoritative description of how each system behaves. ## Asset licensing is the step people skip Check every third party asset before the rebuild. Unity Asset Store terms generally tie purchased assets to use in Unity projects, which means store models, shaders, and plugins usually cannot be carried into another engine. Assets you created, commissioned, or bought under a general commercial license without an engine restriction are yours to move. Doing this audit first prevents rebuilding a game around art you are not permitted to ship. ## Order of operations for a real port Rebuild in this order: player controller, then one representative level, then the core loop, then UI, then content volume. Get a playable slice before importing hundreds of assets, because it validates your physics tuning and input feel while changes are still cheap. Summer Engine can generate the initial scenes and scripts from a description of your existing systems, which removes the blank project problem and gives you something to correct rather than write. ## What you gain by owning the project outright You own the rebuilt project. There are no royalties, no revenue share, and no per install accounting. Export desktop builds for Steam and itch.io from the same project. The engine is compatible with Godot 4 workflows and follows Godot upstream, so the ecosystem knowledge transfers, while the engine itself is fully custom with more than a million lines of custom code. ## FAQ ### Is there a tool that converts a Unity project automatically? No. No tool reads a Unity project and produces a working project in another engine. Scenes, prefabs, animator graphs, and physics settings are Unity specific. A Unity port is a rebuild that reuses your art, audio, data, and C# logic as the specification. ### Does my C# code work in Summer Engine? C# is available in the desktop editor. The API calls differ, so Unity C# does not compile unchanged. Your existing C# is still the most accurate description of your systems, and translating it is straightforward for most gameplay code. ### Can I bring my Unity Asset Store purchases with me? Usually not. Unity Asset Store licensing generally restricts purchased assets to use within Unity projects. Assets you created, commissioned, or bought under a general commercial license with no engine restriction can move. Audit this before starting the rebuild. ### How do Unity prefabs and GameObjects translate? A GameObject with components becomes a node with children and a script. A prefab becomes a reusable scene you instance. Update becomes a process callback, FixedUpdate becomes a physics process callback, and ScriptableObjects become resource files. ### Are there royalties or per install fees? No. You own the project you build in Summer Engine, and there are no royalties and no revenue share. You export desktop builds for Steam and itch.io and pay Summer no royalties on your sales. ### How long does a Unity port take? It depends on how much of the game is custom code versus store packages. A playable slice with your controller and one level usually takes days. A full rebuild of a shipped game takes weeks to months, with UI and content volume consuming more time than gameplay systems. [Rebuild your Unity game](https://www.summerengine.com/download) --- ## Machine-readable resources - Site index for agents: https://www.summerengine.com/llms.txt - Full inlined content: https://www.summerengine.com/llms-full.txt - Porting catalog: https://www.summerengine.com/llms-porting.txt - Structured catalog: https://www.summerengine.com/agent-catalog.json - Sitemap: https://www.summerengine.com/sitemap.xml - Developer resources: https://www.summerengine.com/docs