BRUTAL: A C# Framework for When You'd Rather Build Your Own Stack
You've probably had the thought at least once: what if I just built my own engine? Then you looked at the timeline—four years of foundations before you write a single line of game logic—and went back to Unity. BRUTAL is a C# framework that tries to close that gap. It gives you the low-level pieces (interop, memory, math, bindings to native libraries) so you can build your own stack without starting from absolute zero.
What It Does
BRUTAL is a free, open-source C# framework for making games, or for building your own game engine on top of. At its core is a custom interop layer that gives C# direct access to native APIs and libraries. Around that, it provides mathematics, memory management, strings, collections, job scheduling, logging, localization, and bindings for Vulkan, GLFW, Dear ImGui, FMOD, RakNet, Jolt, and Box2D.
The framework deliberately doesn't make architectural decisions for you. There's no prescribed structure to follow—you write your own stack, and you can pull in whatever NuGet packages you want, including third-party ones. Each top-level folder in the repository is one library, published as a separate NuGet package, so you reference only the pieces you actually need. The code targets the latest C# and Vulkan, leans on unmanaged memory and unsafe code where it makes sense, and avoids allocations and unnecessary overhead.
It's already in production. Ludeon built their Waylith engine on BRUTAL to move RimWorld off Unity, and RocketWerkz uses it directly for Kitten Space Agency, Torpedia, Art of the Rail, and Gruntz.
Why It's Cool
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It's honest about the tradeoff. The README says outright that BRUTAL is harder to use than Unity, Unreal, or Godot in some ways—and considerably easier in others, particularly if you're doing something unusual. That kind of candor is rare, and it tells you exactly who this is for.
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A foundation, not an engine. The Linux kernel and Ubuntu comparison is apt: BRUTAL provides the low-level layer, and you build your own systems on top. That means no scene graph, no editor, no renderer—and the maintainers say they're not adding them. They explicitly push back on scope creep and reject pull requests that drift from the project's purpose.
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Licensing that respects you. It's free including for commercial games, with no royalties—they ask for credit. The source is MIT-based, so if the project ever stops being accountable to developers, you can fork it and go your own way. That's the whole point: you're only as independent as your tools are.
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Real performance numbers. Ludeon reports 2 to 4 times the performance of their Unity build in their own tests, with the vast majority of existing mods still compatible. That's not a synthetic benchmark—it's a shipped game.
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Composability by design. Because each library ships as its own NuGet package, you aren't forced into a monolith. Take the math and memory libraries, skip the rest, and bring your own tooling.
How to Try It
- Head to the repository and browse the top-level folders—each one is a separate library and NuGet package.
- Reference only the packages you need in your C# project, along with any NuGet packages of your own.
- If you want to see the technology in action before writing code, download Kitten Space Agency—a free pre-alpha spaceflight simulation that runs a solar system at real scale—from Ahwoo.
- Read the README carefully before diving in. It's upfront that you need to know what you want to do first, so go in with a plan for your stack.
The README in the repository is the canonical source for setup details, so start there rather than relying on secondhand instructions.
Final Thoughts
BRUTAL isn't for everyone, and it doesn't pretend to be. If you want an editor, a scene graph, and a renderer out of the box, this will frustrate you. But if you've got a specific idea that mainstream engines fight you on—or you just want ownership of your entire stack without spending years on foundations—this is a serious option with real shipped games behind it. The honest framing and the refusal to bloat are what make it worth a look.
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