The Immense engine: a European game engine taking on Unreal and Unity

For decades, game developers have built their worlds on foundations controlled by a small number of powerful technology companies. Whether it is a blockbuster action game, a mobile hit, a virtual reality training tool or an architectural simulation, the chances are high that it was made with either Unreal Engine or Unity. These engines have become so familiar that they almost feel invisible. Developers open them, artists build inside them, students learn them and studios plan entire businesses around them. Now, one of Europe’s most experienced game developers wants to change that. Arjan Brussee, co-founder of Guerrilla Games and a former veteran of Epic Games, is working on The Immense Engine, a new 3D engine being positioned as a European alternative to Unreal and Unity. It is an ambitious pitch: a game engine built in Europe, hosted in Europe and designed with European rules, standards and values in mind. In an industry where the most important creative tools are often controlled by American companies, that idea immediately stands out. But it also raises a difficult question. Can Europe really build an engine capable of competing with the giants?

Why this is about more than games

At first glance, The Immense Engine sounds like a games industry story. In reality, it belongs to a much wider conversation about technology, independence and control. Game engines are no longer used only to make entertainment products. The same real-time 3D technology that powers open-world adventures and online shooters is now used in military training, logistics, architecture, medical visualisation, film production, industrial design and digital twins.

That makes engine technology strategically important. If companies and governments rely on real-time 3D tools to simulate factories, train workers, visualise cities or model defence scenarios, then the question of who owns those tools becomes more serious. It is no longer just about whether a game looks good. It is about where data is hosted, which laws apply, how secure the systems are and how much control users have over the technology they depend on. This is where Brussee’s project taps into a broader European concern. Across cloud computing, artificial intelligence, chips and digital infrastructure, Europe has become increasingly aware of its dependence on technology built elsewhere. The Immense Engine appears to be part of that same mood: a belief that Europe should not only regulate digital platforms, but also build more of its own.

What is The Immense Engine?

The Immense Engine is a proposed European 3D engine led by Arjan Brussee, best known as a co-founder of Guerrilla Games and a former senior figure at Epic Games. The project is being presented as a European-built and European-hosted alternative to Unreal Engine and Unity, with a focus on real-time 3D worlds, AI-assisted development and alignment with European rules and standards. At this stage, it remains an early project rather than a proven commercial engine. There is not yet a public product that developers can properly test, and many important details, including pricing, licensing, platform support and release timing, are still unclear.

A developer with serious history

Brussee’s name gives the project credibility. He is not a newcomer making a bold announcement from outside the industry. His career reaches back to the 1990s, when he worked with Epic on Jazz Jackrabbit, one of the studio’s early successes before it became the Unreal Engine powerhouse known today. He later helped found Guerrilla Games, the Dutch studio behind Killzone and Horizon, before returning to Epic in senior roles connected to Unreal Engine. That experience matters because building a game engine is not like building a single game. A game can be designed for one genre, one art style or one type of player. An engine must serve thousands of different needs. It has to support programmers, artists, designers, animators, audio teams, producers, technical directors and quality assurance testers. It has to work across different hardware, different platforms and different production pipelines. In other words, Brussee understands the mountain he is trying to climb. He has worked inside the kind of company The Immense Engine would have to challenge.

Unreal and Unity are big!

The biggest difficulty for The Immense Engine is that Unreal and Unity are not simply pieces of software. They are ecosystems. A studio choosing Unreal is also choosing a vast marketplace of assets, plug-ins, tutorials, documentation, support services and developers who already know how to use it. A studio choosing Unity is choosing years of community knowledge, mobile support, educational material and workflows that have become familiar to small teams and independent creators around the world.

This gives both engines enormous power. It also creates enormous inertia. Developers do not change engines because a new product sounds interesting. They change when the benefits are strong enough to justify the risk. Once a studio has trained its staff, built internal tools, purchased assets and committed years of work to a particular engine, moving to another one can be expensive, disruptive and sometimes impossible. That is why The Immense Engine cannot succeed on technical ambition alone. It will need documentation, learning resources, stable tools, fair business terms, strong platform support and a community that developers can rely on. It will need to convince studios that it is not only impressive today, but dependable tomorrow.

Why choosing an engine is such a big decision

A game engine shapes almost every part of development. It affects how environments are built, how characters move, how lighting behaves, how physics work, how sound is handled and how a project is eventually shipped. It also affects business decisions. Studios need to know what royalties they may have to pay, what platforms they can release on, how easy it will be to hire experienced developers and whether the engine company can be trusted not to change the rules halfway through production. For a small team, the wrong engine choice can waste months. For a large studio, it can cost millions.

Unity’s troubles created an opening

Unity is especially important in this story because it shows how quickly trust can be damaged. For years, Unity was loved by many independent developers because it felt accessible. It was easy to learn, flexible across platforms and supported by a huge community. Mobile studios, student teams and small developers used it because it allowed them to build quickly without needing the resources of a major publisher. That relationship was shaken in 2023, when Unity announced a controversial Runtime Fee that would have charged developers based on game installs once certain thresholds were reached. The backlash was immediate and intense. Many developers feared unpredictable costs and worried that Unity had changed the rules after they had already committed their projects to the platform. Although Unity later cancelled the Runtime Fee, the controversy left a mark.

For a new engine such as The Immense Engine, that matters. It suggests there may be developers who are more open to alternatives than they once were. Some studios may now care more about licensing clarity, long-term guarantees and transparency. A European engine that presents itself as stable, predictable and developer-friendly could find an audience among teams that feel uneasy about depending entirely on existing platforms. But Unity’s experience also contains a warning. Even a widely used engine with millions of users can lose goodwill quickly. Trust is hard to build and easy to break. Nonetheless, Unity is making significant strategic moves, and from an investor’s perspective, its future outlook appears increasingly bullish.

The Unreal problem

If Unity represents accessibility, Unreal represents power. Epic’s engine has become closely associated with high-end visuals, cinematic presentation and large-scale 3D production. It is used not only in games, but also in film, television, architecture, automotive design and live events. Unreal’s reach has grown far beyond its origins as a shooter engine. This makes it an extremely difficult rival. Unreal benefits from Epic’s money, Fortnite’s success, a huge developer community and years of investment in real-time graphics. It is not perfect, and not every project needs its level of complexity, but it has become the default choice for many studios that want cutting-edge presentation and strong cross-industry support.

For The Immense Engine, competing with Unreal does not necessarily mean beating it at its own game on day one. That would be unrealistic. A smarter route may be to offer something different: stronger European data control, AI-first workflows, specialised simulation features or licensing terms that appeal to studios and public-sector users. The new engine will need a reason to exist that goes beyond simply being “Europe’s Unreal”.

The promise and risk of AI

One of the most interesting parts of The Immense Engine is its planned focus on artificial intelligence. Brussee has suggested that the engine will be built with AI from the beginning, rather than treating it as an add-on. The idea is that AI agents could help developers create, organise, test and maintain complex 3D worlds more efficiently. That could be a major advantage if it works. Modern game development is slow, expensive and often brutally complex. Large productions can involve hundreds of people and years of work. Smaller studios are expected to produce more ambitious games with fewer resources. If AI can reduce repetitive tasks, help generate systems, assist with debugging or make tools easier to use, it could change the economics of development.

However, AI also creates new problems. Game development requires precision. Developers need to understand why something works, why it breaks and how to fix it. If AI-generated systems are difficult to inspect or unpredictable in production, they could become a liability. Studios cannot rely on magic when a console certification deadline is approaching or a live game update has broken core features. The most useful AI tools in game development will not be the ones that simply promise miracles. They will be the ones that make skilled developers faster while still leaving them in control.

The big unanswered questions

The Immense Engine still has many questions to answer before it can be judged as a serious rival to Unreal or Unity. Can it support commercial PC, console, mobile and VR projects? Can it offer tools that artists and designers actually enjoy using? Will its AI features be transparent enough for professional teams to trust? What will the licensing model look like? How will it build a community? Can it attract plug-in makers, asset creators and educators? Will it remain genuinely European if parts of its AI or cloud infrastructure depend on non-European technology? These questions are not criticisms. They are the realities every new engine faces.

Why building an engine is brutally difficult

The history of game development is full of engines that looked promising but never became industry standards. Some were visually impressive but too difficult to use. Some worked well for one studio but failed to attract outside developers. Some had strong technology but weak documentation. Others simply arrived too late, once developers had already committed to more established platforms. A modern engine has to do many things well at the same time. It must be powerful but approachable, flexible but stable, ambitious but predictable. It needs rendering, physics, animation, scripting, asset management, networking, audio, profiling, debugging, version control integration and build systems. It must handle huge projects without collapsing under their complexity.

Then there is the human side. Developers need tutorials, forums, examples, support teams and clear answers when something goes wrong. They need confidence that bugs will be fixed, updates will not break everything and the company behind the engine will still exist years later. This is the unglamorous truth of engine development. Beautiful screenshots get attention, but reliable tools win loyalty.

Europe has a chance, but not an easy one

The Immense Engine arrives at a fascinating moment. Developers are questioning the power of large platforms. Governments are thinking more seriously about digital sovereignty. AI is changing how software is made. Real-time 3D technology is spreading into industries far beyond gaming. All of these trends create space for a new kind of engine. Europe also has strong creative and technical talent. Studios across the continent have produced world-class games, from the Netherlands and Poland to France, Germany, Sweden, Finland and the United Kingdom. The idea that Europe lacks the talent to build serious game technology is clearly wrong. The harder question is whether that talent can be organised into a product with enough funding, support and long-term commitment to compete globally. Building an engine is not a one-year project. It is a long campaign. It requires patience, money, trust and constant improvement.

A bold start, not yet a revolution

For now, The Immense Engine is best understood as a bold statement of intent rather than a finished challenge to Unreal or Unity. It has a compelling story, an experienced figure behind it and a clear connection to some of the biggest issues facing the technology industry. What it does not yet have is proof. That proof will come only when developers can use it, test it, break it, build with it and decide whether it makes their work better. The games industry is full of people who admire ambition but depend on reliability. They will not adopt a new engine because it sounds important. They will adopt it if it helps them ship.

Still, the project is worth watching closely. If Brussee and his team can turn the vision into practical software, The Immense Engine could become more than a European alternative to Unreal and Unity. It could become part of a wider shift in how Europe thinks about creative technology, AI and control over digital infrastructure. The dream is easy to understand: a powerful European engine for the next generation of real-time 3D worlds. The challenge is everything that comes after the announcement.