Ex-Epic Veterans Detail AI-Native Immens Engine as First Demo Nears

Three veterans of Epic Games‘ Unreal Engine team have laid out the first detailed picture of Immens, the engine they have been building since April 2026, and say a first proof-of-concept demo will arrive before the end of August 2026. In an interview with GamesIndustry.biz published August 18, 2026, CEO Arjan Brussee, CTO Michal Valient, and chief product officer Sjoerd De Jong described an engine designed so that small teams can extend it with AI assistance, and said work on it is already running ahead of the schedule they set themselves.

The demo is a proof of concept showing “the flow of editing something” using generative AI. Brussee told GamesIndustry.biz that when the team started in April, it expected the milestone to take until the end of the year. “So we’re already two times faster than we anticipated we would go,” he said. “So it’s really hard to make a reasonable statement about timelines.”

The trio’s pitch starts from a market they describe as consolidated. Unity and Unreal were used to make roughly 70% of the games released on Steam in 2025, per GameDiscoverCo’s scan of more than 33,000 Steam titles, which put Unity at 49.4% of released games and Unreal near 20%. De Jong, who spent 27 years working with Unreal Engine, told GamesIndustry.biz that “standardisation and consolidation” gave the industry a “solid foundation,” but that “now we need innovation, not standardisation.”

An Engine Designed So AI Can Extend It

Valient is careful about what “AI-powered” means here. Immens is not, he says, about prompting games into existence. “The AI in Immens is about building the engine in a way that is really extensible,” he told GamesIndustry.biz. “If we design the code base with this in mind, then even smaller teams or individuals can come and extend the engine. They are not just limited to a bit of scripting that they can do.”

The company’s own site describes the same architecture in plainer terms: text-based, open-standard formats with full API interoperability, so that external tools can read and edit game content directly. Brussee’s argument is that engines have been the “weird outlier” in a toolchain where Blender, Maya, and other packages increasingly speak open formats. “The moment you have files that are text based, anything can read it,” he said. “If you want to use something like Blender or Maya or generative stuff or our own stuff, you can just plug it in.”

De Jong frames the target as the opposite of what he calls the “monolithic approach” of current engines, where developers adapt to the software and its proprietary file formats. The Immens editor and content pipeline are built on Python and standard asset formats, and the company says users decide how much AI enters their workflow, and where.

The site also lists technical ambitions the interview only touches: real-time global illumination, neural super-resolution, and raytracing as a baseline, plus hot-reloading and an engine that “boots in seconds.” The site describes Immens as ‘still in its early days,’ with progress updates promised soon.

The Founders Behind Immens

The three founders’ histories run through most of the industry’s engine story of the past two decades, per their official bios. Brussee spent eight years at Epic as technical director and director of product management for Unreal Engine, where he helped ship UE5 and led the port of Fortnite Battle Royale to mobile, Switch, and next-gen consoles. Before that he co-founded Guerrilla Games, launched the Killzone franchise, served as executive producer on the Battlefield series at Electronic Arts, and co-founded Boss Key Productions.

Valient spent nearly seven years at Epic as senior director of engineering, heading teams behind core Unreal Engine components and serving as engineering director on demos including The Matrix Awakens and Lumen in the Land of Nanite. Before Epic he worked at Apple on GPU features behind Metal 2 and Metal 3, and spent a decade at Guerrilla leading technology on the Decima engine.

De Jong spent 12 years at Epic as senior director for developer experience, first as Unreal Engine’s evangelist and later founding the Epic Developer Community platform, which the company says serves more than 200,000 developers a month.

What the First Demo Sets Up

Immens is still small: the three founders plus what they describe as some “helpers,” a size De Jong calls deliberate. “Making an engine is a very complex endeavour, so you can’t just throw a million people at it and expect it to work,” he said. “On the other hand, there is a window of opportunity here over the next few years.”

The founders told GamesIndustry.biz the company has its first funding commitments, with the amount described only as “reasonable.” On a business model, Brussee said the team admires Epic’s “we succeed when you succeed type approach” but that it is too early to commit to one; Unreal Engine itself is free to start, with a 5% royalty only once a title grosses over $1 million, per Epic’s licence terms.

The immediate marker is the August 2026 proof of concept, the first public test of whether an engine built for AI-assisted extension behaves the way its founders describe. The company says it will share further progress after that.