Someone made a CAPTCHA where you play Doom on Nightmare difficulty
by Samuel Axon from Ars Technica - All content on (#6T9TC)
People have been complaining for a while that passing a CAPTCHA is too difficult, but developer and tech CEO Guillermo Rauch has made one of the hardest yet: a fully playable CAPTCHA based on the classic PC game Doom.
It's been a long-running joke that developers will make Doom run on absolutely anything, so it's not much of a surprise that it's now running inside something that resembles a CAPTCHA.
The app essentially amounts to a small Doom level that is playable with keyboard controls (arrow keys to move, space bar to shoot) within a CAPTCHA-like presentation. You must kill three enemies to pass the test.