Is Building a Custom Game Engine Worth It? Lessons from Soup Raiders' Native Migration

From Web to Native: The Decision to Build a Custom Engine

In game development, choosing a mature commercial engine (like Unity or Unreal) is almost the industry default. However, the developer of the indie game Soup Raiders made an unusual decision—abandoning off-the-shelf engines in favor of building a custom game engine, migrating the game from a Web version to a native implementation. This story, which sparked over 50 comments on Hacker News, reveals a core question: in an era where mature engines are readily available, why would anyone still want to build their own technical foundation from scratch?

The answer isn't simply "an obsession with reinventing the wheel"—it's about a deep trade-off involving control, performance, and long-term maintainability. When a game demands unique technical capabilities, or when developers want to thoroughly understand and optimize every component, building a custom engine transforms from a luxury into a rational choice. This isn't an isolated case in the indie game world—Jonathan Blow developed custom engines for Braid and The Witness, Noita built the Falling Everything Engine to achieve its signature pixel-level physics simulation, and Celeste uses a lightweight engine based on the FNA framework. These cases collectively demonstrate that when a game's core mechanics need to push beyond the boundaries of general-purpose engines, custom development often becomes the necessary path to realizing the creative vision.

Tangible Benefits of Going Native

Significant Performance and Experience Improvements

The most immediate benefit of migrating from a Web tech stack to native implementation is at the performance level. While browser-based runtime environments offer convenient deployment and cross-platform friendliness, they also introduce significant overhead: JavaScript runtime limitations, rendering pipeline abstraction layers, and a ceiling imposed by the inability to directly access underlying hardware.

To understand the technical roots of this gap, you need to recognize that the Web tech stack (typically HTML5 Canvas/WebGL + JavaScript/TypeScript) runs inside a browser sandbox. Although technologies like WebAssembly have dramatically improved performance, they remain constrained by the browser's security model and abstraction layers. JavaScript uses a single-threaded event loop model (though Web Workers provide limited multi-threading capability), and its garbage collection mechanism causes unpredictable frame rate fluctuations—which is fatal for game experiences. Native development (typically using system-level languages like C/C++/Rust) allows direct memory management, precise thread scheduling control, and bypasses the browser intermediary to interact directly with the operating system and hardware.

After going native, games can directly call graphics APIs (such as Vulkan, Metal, or DirectX), achieving lower input latency, more stable frame rates, and finer-grained memory management. It's worth noting that Vulkan (maintained by Khronos Group), Metal (Apple proprietary), and DirectX 12 (Microsoft) represent the evolution of modern low-level graphics APIs. Their core difference from the previous generation of OpenGL/DirectX 11 lies in giving developers more GPU control. Developers must manually manage command buffers, synchronization primitives, memory barriers, and other low-level details, gaining lower driver overhead and more predictable performance in return. For action games that emphasize immediate feedback, these improvements are often experience upgrades that players can directly perceive.

Complete Technical Control

When using a third-party engine, developers are essentially working within someone else's framework. When encountering engine bugs, performance bottlenecks, or missing features, you're often stuck waiting for official fixes or resorting to roundabout workarounds. A custom engine means every line of code is under your control—no black boxes, no unexplainable behavior, and any issue can be traced back to specific implementation details.

This control is particularly valuable in long-term maintenance. Commercial engine version upgrades sometimes introduce breaking changes, forcing projects into large-scale adaptation. A custom engine evolves entirely at the project's own pace. A typical example is the Runtime Fee controversy that Unity triggered in 2023—an engine vendor's business strategy changes can directly impact the cost structure of already-launched games. Additionally, Unity's migration from the built-in render pipeline to URP/HDRP, and Unreal Engine's Nanite/Lumen architecture changes from UE4 to UE5, have both forced numerous projects into costly adaptation work. This passive dependence on third-party technology roadmaps is one of the key reasons many experienced developers turn to custom engines.

The Real Cost of Building a Custom Game Engine

Development Time and Engineering Complexity

The discussion wasn't without sober voices: building a custom engine is by no means a free lunch. Rendering systems, physics engines, asset loading, audio, input handling, cross-platform adaptation—each subsystem represents the result of hundreds of person-years of refinement in mature engines. If indie developers want to rebuild everything from scratch, it means a massive shift of effort from "making games" to "making tools."

Specifically, a complete game engine typically contains over a dozen core subsystems: renderer (including shader compilation, material systems, lighting models), physics simulation (collision detection, rigid/soft body dynamics), audio engine (spatialized mixing, streaming), asset pipeline (async loading, hot reload, format conversion), scripting systems, network synchronization, UI frameworks, animation state machines, scene management and serialization, and more. Teams like id Software's id Tech and Epic's Unreal Engine typically have core technology teams ranging from dozens to hundreds of people. Indie developers building custom engines usually adopt a "good enough" strategy, implementing only the subset of subsystems required by the project rather than pursuing comprehensive general-purpose capability.

Therefore, the viability of a custom engine depends heavily on the game's positioning. For projects with relatively unique gameplay mechanics or distinctive technical requirements, a customized engine can precisely fit the needs. For projects aiming for quick launch with conventional gameplay, mature engines remain the more pragmatic choice.

Lack of Ecosystem and Toolchain

Another major advantage of mature engines lies in their vast ecosystem: editors, asset stores, community plugins, debugging tools, and extensive tutorials and documentation. Custom engines require developers to build all this supporting infrastructure themselves, or accept working without tool support. The impact on development efficiency should not be underestimated.

When Should You Consider Building a Custom Game Engine?

Synthesizing the community discussion, a custom engine is more suitable for the following scenarios:

• Highly customized technical presentation: The game's core selling point relies on unique rendering or simulation effects that existing engines struggle to achieve.
• Extreme performance requirements: You need to squeeze every bit of hardware performance and cannot accept the abstraction overhead of general-purpose engines.
• Learning and control purposes: Developers want to deeply understand game fundamentals and have complete control over the codebase.
• Long-term project maintainability: You don't want to be subject to third-party engine business strategies, licensing fees, or version changes.

Conversely, if the goal is to validate gameplay as quickly as possible, control development costs, or the team lacks low-level systems experience, then mature engines remain the wise choice.

Conclusion: There's No One-Size-Fits-All Answer for Engine Selection

Soup Raiders' native migration provides a valuable case study: the benefits of a custom engine are real, but so are the costs. What you gain is performance, control, and long-term autonomy; what you pay is time, engineering complexity, and the absence of ecosystem support.

For most game developers, this isn't a moral question of "should I reinvent the wheel" but rather an engineering trade-off that must consider project goals, team capabilities, and time budget. True wisdom lies not in which path you choose, but in clearly understanding the costs and rewards of each path, and making the most fitting judgment for your project.