From http://en.wikipedia.org/wiki/Radirgy :

An arcade shmup developed by Milestone Inc. in 2005 using the Sega NAOMI arcade system board. A Dreamcast port was released two years later.

A North American release of the game - titled Radio Allergy - was scheduled for early 2007 on the Gamecube but failed due to lack of interest. However, it is one of the featured games on the Ultimate Shooting Collection for the Wii and will have a sequel.
radirgy