Darius II, released in Japan, is a significant advancement over its predecessor, retaining the core gameplay mechanics while incorporating a number of improvements. The gameplay likely includes more challenging enemy patterns, updated visuals, and potentially enhanced audio. This Japanese version offers the base upon which other versions were later built.

Darius II (Japan)

Darius Gaiden - Silver Hawk Extra Version (Ver 2.7J 1995/03/06) (Official Hack)