RocketWerkz open-sources BRUTAL, its C# framework built without Unity or Unreal

RocketWerkz and Ahwoo—the two companies founded by DayZ veteran Dean Hall—have released their C# game development framework BRUTAL as open source, free for commercial use with no royalties. The only license obligations: attribution and a displayed logo before gameplay loads.

BRUTAL is not a game engine. It's a programming framework: C# and .NET combined with C++ libraries and low-level graphics access, designed as a foundation developers can use to build proprietary engines or write games from scratch. RocketWerkz uses it in-house for Kitten Space Agency. The most visible external case study is Ludeon Studios, which announced last week that it ported RimWorld off Unity onto a new engine called Waylith—built on BRUTAL—claiming better performance and faster start-up times than previous versions.

Why are studios looking at alternatives to Unity and Unreal?

Timing matters here. The Unity Runtime Fee saga and Epic Games' announcement that it will deprecate Blueprints in Unreal have pushed some developers to question the stability of their tech stacks. Hall himself clashed with Unity in 2025, alleging the company threatened to terminate RocketWerkz' license over what he called false accusations of terms-of-service violations.

"You are only as independent as your tools are," Hall said in the announcement. He added that while not every developer should have to make their own engine, every developer should have "the option to do so."

That sentiment already has converts. Mega Crit switched from Unity to Godot while making Slay the Spire and barely lost development time in the process.

What does BRUTAL change for studios?

In practice, it lowers the barrier to engine ownership for teams comfortable in C#. But it demands more than adopting Godot. There's no editor, no out-of-the-box toolchain—developers must build and maintain their own tools on top of the framework, which means a genuine willingness to work with the nuts and bolts of the language.

Hall has pointed to an unexpected accelerator: large language models. In 2025, he and Kerbal Space Program creator Felipe Falanghe told Game Developer that LLMs made working with BRUTAL much easier, because C# libraries and Vulkan documentation are both "highly structured, with very clear syntax."

"An LLM is essentially tokenizing language, then putting masses of vectors around that to build linkages between those tokens," Hall said. "What could be better than a highly-structured, in fact brutally structured language?"

Both men stressed this isn't "vibe-coding"—automatically generating code from prompts. The AI serves as a reference tool, not a code generator.

Is BRUTAL trying to become an industry standard?

No—and Hall says that's deliberate. He told Game Developer last year he'd prefer other developers create their own simpler frameworks following a similar approach, rather than adopting BRUTAL as a standard.

"BRUTAL was made to deliver a very specific, kind of hard-to-make game where you need to sit down and ask a whole bunch of questions [about how it works]," he said.

Some teams will welcome that rigor. Others will tap out. What's worth watching is whether the Ludeon port prompts more mid-sized studios to evaluate custom-engine routes—and whether Unity and Epic respond to the growing perception that third-party engine dependency is a business risk.