A Helsinki-based startup just built an AI copilot that lets Unity developers build games by simply describing what they want.
Nimble Fox is releasing its AI-powered Unity development tool to the public on Sept. 7, letting developers build and modify games by prompting directly inside the game engine. The platform will have free and paid plans at launch.
Rather than generating a full game in one pass, Nimble Fox lets developers build feature by feature, implementing gameplay mechanics, UI flows, and other scoped changes one at a time. Built into the Unity editor, the tool reads the context of an existing project and makes changes through natural-language prompts, working with code, art and assets already present or generating what’s missing. The company is backed by Sisu Game Ventures, Wave Ventures, and First Fellow Partners.
Nimble Fox founder and chief executive officer Jonne Myöhänen started the project after growing frustrated with how long it took to turn a game idea into something playable.
“I had a lot of ideas for games, but I didn’t want to spend months just prototyping them,” he said in a press release. “I started building Nimble Fox as a faster creative outlet for game development.”
The project turned into a company after Myöhänen won Aalto Entrepreneurship Society’s Ignite accelerator in autumn 2025. Nimble Fox went on to raise a funding round, grow into a six-person full-time team in Helsinki, and secure an R&D grant from Business Finland.
Myöhänen framed Nimble Fox’s ambitions as going beyond code generation.
“We see a much bigger opportunity than AI simply generating code,” he said. “The useful part is having AI do the necessary work across the Unity project to turn a request into something that actually works in the game, rather than just writing code.”
Nimble Fox is built around workflows that developers and studios say take disproportionate amounts of time, with the goal of cutting manual work without pulling creative control away from developers. The company is also exploring dedicated versions of the tool configured for individual studios’ larger games, where it could take a feature request and implement a working first version directly inside that studio’s project.
Myöhänen is currently in San Francisco through the Silta Program, a house for early-stage founders from Finland, meeting with game studios to introduce Nimble Fox to the U.S. market ahead of the Sept. 7 public launch.
To mark the release, Nimble Fox is hosting the Nimble Game Jam, a 48-hour hybrid event running between September 4-6 in Helsinki and online. Participants get free access to Nimble Fox for the duration of the jam and build games over the course of the weekend. The jury includes Samuli Syvähuoko, Jonne Taivassalo, and Ignacio Amaya.
Nimble Fox plans to continue developing the tool based on customer feedback and the workflows where the technology creates the most value for developers, the company said in the press release.
Nimble Fox’s approach places it among a growing number of startups building AI tools tailored to specific game engines rather than general-purpose code generators, as studios look for ways to speed up production without ceding creative decisions to automated systems.