Red Wave is yet another hack, but it doesn't really push the boundaries as much as Black Belt Edition or Koryu. You can do any special move in the air, but you can't have multiple projectiles on the screen with most characters (Sagat is a notable exception to this).
You can change character by holding down the start button. This hack is well known for how difficult it is, as the CPU seems to have been set on the highest difficulty setting possible. The default high score is now over 2 million points, which is a rather high score to beat.
Charge times for certain moves were also removed, so Guile, for example, can do his somersault kick just by pressing down, up and kick. Other moves have different features, such as projectile attacks homing in on the opponent, or Ryu's hurricane kick sending him flying across the screen.