A new CAPTCHA has been created by Guillermo Rauch that is based on the classic PC game Doom, making it one of the hardest CAPTCHAs yet. The app presents a playable version of the popular game within a CAPTCHA-like format. Players must navigate through a level filled with enemies and kill three to pass the test.
The Nightmare difficulty level makes the challenge extremely hard, requiring multiple attempts to overcome. Since strafing is not allowed, players must find other ways to evade enemy fire, leading to a steep learning curve. Users are sharing strategies on the Hacker News thread, showcasing just how difficult this CAPTCHA has proven to be.
Source: https://arstechnica.com/gaming/2025/01/someone-made-a-captcha-where-you-play-doom-on-nightmare-difficulty