The series takes place during the events of a war between humans and the Belsar empire, which plot to destroy all that is left of mankind.

Darius is known for its branching stage paths, upbeat soundtrack, and cute sea life-inspired enemies.

[2] The series first appeared in Japanese game centers in 1987, where Darius became known for its "colossal" triple-screen arcade machine setup and body-sonic seats.

Compared to the technology of Ultra Panavision 70 in how the series utilized color, it also used an "innovative" branching stage format that allowed for multiple playthroughs to be different in major ways.

The series' use of robotic fish, crustaceans, and other sea creatures as enemies was cited as a way to make the games stand out due to the proliferation of sci-fi arcade shooters in the mid-1980s'.