Street Fighter II: The World Warrior · Super Nintendo (SNES) · 1992
A button sequence entered while the Capcom logo flashes on boot turns the screen blue and unlocks hidden match options the standard game keeps locked, including same-character battles.
The SNES port of Street Fighter II hides a configuration code behind the Capcom logo that appears as the system boots. Inputting the precise sequence during that brief window flashes the screen blue to confirm it registered, then exposes options Capcom left out of the normal front end — most famously the ability to pit a character against a mirror copy of themselves, something the arcade original did not allow. The code spread rapidly through schoolyards and early-1990s magazine tip pages, becoming one of the defining "secret handshakes" of the SNES Street Fighter community and a reminder that home ports often shipped with hidden toggles the arcade boards never exposed.
When the Capcom logo appears as the game boots (before the title screen), press Down, R, Up, L, Y, B. If entered correctly the screen turns blue to confirm, and the hidden options become selectable from the game's menus.