Koryu is a hack that may have only been released in Taiwan, not much is known about where it originated from. But it has been ROM dumped since and a lot of people see it as the best hack of the game due to the ridiculous gameplay, even more silly than in Black Belt Edition.

As well as the usual hack features, such as doing special moves in the air and faster game speed, Koryu has several other changes. Ryu and Ken's dragon punches release a barrage of fireballs, Sagat's tiger uppercut has two yoga flames appear on his legs and you can throw opponents without actually grabbing them. Other differences include Honda's stage now having his ending theme for music, Ryu has a new costume color, the clouds in the stages for Ryu and Blanka now scroll really fast and more.

You could juggle the opponent with ease, charge times for characters were removed (so Bison, for example, can do his psycho crusher just be pressing left, right and punch) and due to a glitch the screen would sometimes go completely black and you'd have to wait for the next round to start to get the picture back. Videos of this hack in action from chanwa1522 and AgentSpinhead.