After Google mapped an adult male fruit fly's brain, software engineers made it play Doom, Mario64, and Beat Saber

Google announced it had fully mapped the brain and central nervous system of an adult male fruit fly into 3D neural shapes, reconstructing over 166,000 neurons using AI to combine millions of 2D images. Researchers described the model as a foundational map that could accelerate understanding of the brain and mark a major milestone in neuroscience. The project was unveiled via HKEPC, highlighting its potential to advance neuroscience research through detailed neural reconstruction.

Within three days of the announcement, software engineer Alex Wormuth at Coinbase trained the fly brain to play the original Doom by mapping each game frame to sensory neuron stimulation and game controls. Damage in the game triggered reinforcement signals to two PPL101 dopamine cells, and the fly’s progress could be viewed in real time on Wormuth’s website, including a third-person render of the fly navigating Doom maps.

Modders expanded the experiment by teaching the fly to play Beat Saber using reinforcement learning, where replays of songs were used to train the fly to hit targets. Lyra Bubbles on X noted that while the fly was not reacting organically to on-screen notes, it was responding to stimuli, with plans to reduce reliance on external signals for fully reactive play.

Jessica Paquette and YouTuber Ro0oney further demonstrated the fly brain’s versatility by running it through Super Mario 64 and Minecraft, respectively. Ro0oney used Flywire.AI, a Princeton University collaboration analyzing a female fruit fly brain with 139,255 neurons, contrasting Google’s male fly brain model with 166,000+ neurons.