More info on IGDB

NOTE: "Darius+" is the Amiga, Atart ST, and ZX Spectrum port of the original Darius published by The Edge and developed by Softek. This is a different port than the title "Darius Plus", which was produced by Bits Laboratory and NEC Avenue for the TurboGrafx-16 PC-Engine. Three PC Engine ports were produced by NEC Avenue for the Japanese market in 1990, titled "Super Darius" on March 16, "Darius Plus" on September 21 and the only commercially-released HuCard that has enhanced support for the PC Engine SuperGrafx, and the limited promotional title of "Darius Alpha (α)". All three PC Engine versions were developed by Bits Laboratory. During the same year, a home computer version of the game titled "Darius+" (unrelated to the similarly-titled PC Engine port) was published by The Edge and developed by Softek for the Amiga, Atari ST and ZX Spectrum in Europe.