Gradius Gaiden (グラディウス外伝) is a horizontal-scrolling shoot-em-up by Konami for the PlayStation and released exclusively in Japan in 1997 (until the Gradius Collection release for the PSP). A side entry to the main Gradius series, it features all-new mechanics, like the selection of playable star ships (the traditional Vic Viper, but also Jade Knight and Falchion β), new weapon types as well as being able to swap items in the player's Power Meter. It is notably also the first Gradius title to feature simultaneous 2-player play.

zggzdydp controls both Jade Knight and Falchion β and completes the game in record time.