In a 1994 interview with the game's planner Hidehiro Fujiwara published in the Gamest mook vol.6, he was asked why the team wanted to make a new Darius game 5 years after the release of Darius II. He responded that because of his heavy involvement in the first two games, he made a new game because he loves the Darius series:

In a 1994 interview with the game's planner/graphics designer Hisakazo Kato published in the Gamest mook vol.6, he insisted that "Darius Gaiden" should not be named "Darius III", because up till then, the Darius series was made with custom multi-screen arcade cabinets, and in their hearts, when they thought of "Darius" they thought of those multi-screen cabinets. Once the team knew the game would be a single screen game, they didn't want to name it "Darius III".

As such, the game's story does not take place after Darius II, and instead takes place between Darius I and Darius II. Plus, with the game being called "Gaiden", the two Silver Hawk pilots have no connection to Proco and Tiat from those games.