Irem began development of
R-Type Delta in early 1998. Around the beginning of its development,
Taito released a conversion of their arcade game
RayStorm for the
PlayStation, whose 3D visuals caught the eye of several video game developers and led to the release of several 3D shooting games for the console. based on the fact three different ships were playable, which reminded him of the Greek symbol
delta. Early planning documents for the game referred to it as
R-Type EVE, a titled named after the novel
Parasite Eve and met with a mixture of confusion from the production team. ==Re-release==