Darius Gaiden (ダライアス外伝) is the third main entry in Taito's Darius series of horizontal space shoot-'em-up games, first released in 1994 in arcades as a sequel to Darius II. During development it was known as Darius III. Why it was changed to a"gaiden" type of story (roughly meaning "side story"), is unknown.
The game's soundtrack was composed by Taito's house band Zuntata.
Gaiden was ported to the Sega Saturn and released in late 1995, curiously arriving before the Saturn port of Darius II. It was the second of two Darius games to be brought to Sega systems - its arcade successor, G-Darius, which used polygonal graphics, skipped the Saturn in favour of the PlayStation in 1998.
Darius Gaiden closely follows the established formula seen in previous Darius entries, but dropped the eye-catching multiple screen setup in favour a simple one-screen solution. The difficulty of the game is considered to be lower than that of Darius II.
So called black hole bombs have been added, that damage enemies and neutralize projectiles, but also sucks in power ups. Not using any of these yeilds a special score bonus at the end of the game, but is tied to not using continues.
Stages are selectable in the usual branching path fashion after defeating a boss, with the "upper" routes typically being easier to clear. However, the upper routes also offer more scoring chances, which goes against the usual risk vs. reward design in arcade games, and as the high score table is not dictated by path, the only reason to use a different route is to see each of the different stages and endings.
Strangely autofire, a common feature in shooting game ports, is missing from options. It must be activated by a cheat code.
The game has a dynamic difficulty level, depending on power ups collected, survival time and so on.