"[Unreal and Unity] get bigger and bigger, [and there's] more and more baggage that builds over time. So you wonder if there's got to be something here where we can [have] a clean, modern engine built from the ground up."
That's Sjoerd De Jong, Epic Games' former Unreal Engine lead evangelist, explaining why he walked away from 12 years at one of the most powerful companies in game development to start from scratch.
De Jong left Epic in June, signing off with a message about the industry reaching a turning point he needed to personally address. At the time, the specifics were vague. Now they're not.
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What the Immens Engine actually is
De Jong's new project is called the Immens Engine, and he's building it with a small team of co-founders that includes Arjan Brussee, a former Epic technical director. The pitch is direct: a game engine built from the ground up, without the decades of accumulated technical debt that Unreal and Unity carry.
Here's the thing about engines like Unreal Engine 5 and Unity. They're extraordinary pieces of software, but they've also been continuously patched, extended, and retrofitted for over two decades. Every new feature gets bolted onto an architecture that predates modern hardware, modern workflows, and modern expectations. De Jong's argument is that this creates stagnation, not just in the tools themselves, but in how developers think about building games.
His goal with Immens is to give developers a more modular foundation, one where they can build a "more bespoke" toolset rather than inheriting a monolithic one. The engine is also being designed from day one to connect cleanly with the external libraries, services, and tools that studios already rely on, rather than expecting everything to run through a single ecosystem.
The AI integration angle (and what it isn't)
De Jong is explicit that Immens is being built with agentic AI workflows in mind. His read on the current situation is that existing engines weren't designed for AI to interface with directly, and that retrofitting AI tooling onto legacy architectures produces friction rather than capability.
Epic itself signaled a major AI direction for Unreal Engine's future, describing a "central role" for LLMs, generative AI models, and tools like Claude and Codex. De Jong's skepticism isn't about AI itself, it's about whether tools designed for human developers can genuinely serve agentic AI without a rethink at the foundation level.
He's also pointed about what he doesn't want: "We don't want [users to] press a button and generate a game, and then release it alongside the other five million games people have made that way." That's a direct shot at the flood of AI-generated content already hitting platforms like Steam, and a signal that Immens is being positioned for serious developers, not content mills.
Why this matters beyond one person leaving one company
De Jong's departure follows a pattern that's worth paying attention to. Earlier this year, former Unreal Engine director Nick Penwarden retired after 15 years at Epic. Epic CEO Tim Sweeney has publicly described a "tidal wave" sweeping over the AAA games business. And Godot, the open-source engine, has been steadily gaining traction as a genuine alternative for developers who want out of the Unreal-Unity duopoly.
The engine market has been functionally locked for years. Unreal dominates the high-end AAA and mid-tier space. Unity owns a huge share of mobile and indie development. Both have had well-documented struggles recently, Unity in particular after its controversial runtime fee announcement in 2023 that sent developers looking for exits. Godot absorbed a lot of that energy, but it's a very different tool aimed at a different segment of the market.
Immens, if it gets off the ground, is targeting something different again: a modern, professionally-oriented engine built for the way studios actually work now, with contemporary external tooling and AI-forward architecture baked in rather than glued on.
For players, the engine underneath a game rarely matters directly. But what most players miss is that engine constraints shape what developers can build, how fast they can build it, and what kinds of creative risks they can afford to take. A genuinely new engine entering the space, backed by someone with De Jong's institutional knowledge of exactly what Unreal does and doesn't do well, is worth watching.
Immens is still early. There's no public release window, no public demo, and the team is small. But the people building it know Unreal's architecture from the inside, and that's not a nothing credential. Keep an eye on the guides hub for coverage as the engine space develops, and if you're playing games built on Unreal Engine 5 right now, our Directive 8020 PC settings optimization guide is a good reminder of just how much headroom modern UE5 titles leave on the table.
