IMMENS

A 3D engine that does not exist yet, announced by three people who between them shipped Unreal Engine 5 and the Decima engine. There is no download, no repository, no licence, no price and no date: the site offers "Request access" and "Read the specs," and says "IMMENS is still in its early days, but things are moving fast." Everything below is the company describing its intentions.

The pitch is "built from first principles: modular, extensible, and open by design," aimed at "faster iteration, greater scalability, and the flexibility modern dev teams demand."

The claims, as made

• Open formats as the interface. "Our text-based, open-standard formats and framework deliver full API and MCP interoperability: plug in the tools that matter, build new ones, and edit your game content directly. Everything open, nothing locked away." Text formats are the load-bearing choice here — everything else on the list follows from content a tool other than the editor can read.
• AI-native by design. "Work with agents in a continuous loop: guide a step, see the result, verify or tweak it, then move on. Every asset and system is fully editable and exposes structured, machine-readable context with full provenance."
• AAA-class rendering: real-time GI, neural super-resolution, diffusion rendering, and raytracing "as a baseline on future consoles," while staying "friendly to mobile platforms."
• Runtime efficiency: "massive-scale simulation with huge concurrent entity counts."
• Instant iteration: boots in seconds, hot reload, moving between editor and running game.
• A Python editor. The editor and content pipeline are "built extensively on Python and standard asset formats," so teams extend the tools "without fighting a monolith."

Not one of these carries a number, a demo, or a named title. That is the correct thing for a page at this stage to contain and it is also the reason this is T3.

Who is making it

The founders are the evidence, and they are unusual for a pre-product engine startup.

• arjan-brussee (CEO) — co-founded guerrilla-games, eight years at epic-games as Technical Director and Director of Product Management for Unreal Engine, where he "helped ship UE5" and led the Fortnite Battle Royale ports to mobile, Switch and next-gen consoles.
• michal-valient (CTO) — nearly seven years at Epic as Senior Director of Engineering over core Unreal components, engineering director on The Matrix Awakens and Lumen in the Land of Nanite; before that Apple (Metal 2 and Metal 3) and a decade at Guerrilla leading the Decima engine's technology.
• sjoerd-de-jong (CPO) — 27 years on Unreal, twelve at Epic as Senior Director for Developer Experience, founder of the Epic Developer Community platform "serving 200,000+ developers a month."

So the team's collective experience is Unreal and Decima, and the product is pitched as a replacement for the kind of engine they spent their careers building. Read the "first principles" framing against that: it is a claim by people with specific knowledge of where the incumbent's foundations hurt, which makes it more interesting than the same sentence from strangers, and no more verified.

Where it lands in this wiki

It is the fourth instance on engine-agent-surface and the first of a different kind. Unreal, Unity and Godot each retrofitted an agent surface onto an engine whose formats and APIs were designed for humans, and that page's four convergent properties are largely accommodations to the retrofit — self-description, extensibility in the project's language, a context budget, and a locked-down write path. IMMENS proposes to start from the other end: text formats an agent can read directly, provenance on every asset, MCP as an interface rather than a plugin.

If it ships and works, it answers the spoke's standing question — is AI tooling a differentiator or table-stakes? — in the strongest way available, since a company betting its existence on the differentiator answer is a different signal from three incumbents adding a plugin. If it does not ship, it answers nothing, which is the state it is in today.

One smaller note, recorded because it is the only unmediated thing on the page: the News section's markup still contains an unfilled template row — "Outlet name", "Headline", "One or two short sentences", dated 1 Jan 2026, next to a comment reading "is optional; delete it if the post has no image", and a press kit advertising "98 logos & brand assets". The real press link under it is a 27 July 2026 This Week In Videogames piece on De Jong leaving Epic to build an engine. An early-days site, exactly as described.

Tier

T3 — first-party marketing for an unreleased product. Usable for what is claimed, and for the verifiable public record of who is claiming it; useless for whether any of it works. Nothing here should be repeated in this wiki as a property of a shipping engine. The re-read that matters is whether "Read the specs" ever leads to specifications.

Related

engine-agent-surface · unreal-engine · epic-games · guerrilla-games · arjan-brussee · michal-valient · sjoerd-de-jong · godot-mcp-toolkit · unity-cli · synthesis