Leo selected GOD MODE . Tarzan’s health bar became a skull icon. He punched a baboon. The baboon exploded into binary code. He selected NO CLIP . Tarzan walked through a baobab tree and emerged inside a developer room—floating islands of unused level geometry, half-finished animations of Jane eating a sandwich, and a single, lonely gorilla named "Test Subject 04."

In the humid, pixelated jungle of 1999, a PC gamer named Leo was stuck. Not on a level—on the tutorial . Disney’s Tarzan had been his birthday gift, a CD-ROM that promised vine-swinging, cheetah-dodging, and the voice of Phil Collins in his ears. But Leo couldn’t get past the first mangrove swamp. Every time he tried to leap from a branch, Tarzan would flail into a hippo’s mouth.

His heart pounded. He typed as instructed: while holding Ctrl + Alt + Shift , he clicked the Konami Code into the number pad. Nothing happened. He tried again. Then, the game glitched. Tarzan froze mid-air, then fell through the ground into a white void.

And Leo would put his hands over his ears, because some games—once you unlock their secrets—start playing you back.