Back in 2021, the internet briefly lost its collective mind over a very particular headline: rats had been trained to play Doom — specifically, Doom II. Four years later, the project is back with a substantial update, and this time it's less of a novelty and more of something that actually resembles gameplay. Kind of. Especially now that an added trigger mechanism allows the rats, which see their way around the game with new wraparound AMOLED screens, to shoot.
The project, led by neuroengineer Viktor Tóth, has evolved into a second-generation setup that significantly expands what the rats can do inside the Doom engine. The original version used a clever but limited configuration: rats stood in a harness over a freely rotating ball, with forward movement mapped to movement through a simplified Doom II corridor. Rewards came in the form of sweetened water dispensed when the rat performed the desired action. It worked, but only that; there was no real interaction with the game's mechanics, so calling it "playing Doom" was overstating the case a bit.
