Digital Fruit Fly Brain Trained to Play Doom, Beat Saber and More
Google's fruit fly brain model has been trained to play Doom and other games, with neural activity mapped to controls.
Wormuth described the setup: "Each Doom frame stimulates sensory neurons," he said. "Neural activity is mapped to game controls. Damage triggers a stimulus to two PPL101 dopamine cells as reinforcement." Since then, the digital brain model has been repurposed to control other games, including Beat Saber and Super Mario 64, PC Gamer reported.
PC Gamer reported that Wormuth's website lets people watch the fruit fly play in real time. The site shows the point of view in Doom and a third-person render of the fly moving around Doom maps. As of the time of writing, the fly was on round 6385 and, in PC Gamer's assessment, was not very good at the game.
Modders have extended the experiment beyond Doom. Lyra Bubbles on X used the brain and replays of a song in Beat Saber to teach the fruit fly where to hit and why through reinforcement learning. That means the fly is not organically reacting to notes appearing on screen, but it is receiving input and responding to stimuli. Lyra said further training is intended to reduce reliance on external signals and allow it to play fully reactively with no input data.
Jessica Paquette, who said they had "pivoted to fly engineering in 2026," also shared on X their experience running the digital fly brain through Super Mario 64. YouTuber Ro0oney put a fruit fly brain into Minecraft, but used Flywire.AI, a similar project made in collaboration with Princeton University.
The projects differ in scale and source: Flywire.AI has more than 160,000 neurons, compared with 139,255 in the Google model, and Google analyzed a male brain while Flywire analyzed a female brain. The basic idea is the same, according to the account.