Radio Zonde is a free shoot 'em up arcade-style game, made by the doujin group Inudon Empire, also known as Ruminant's Whisper, the developers of Hellsinker (and Dogma, a fighting game). It can be considered Hellsinker's spiritual predecessor, featuring similar gameplay elements and artstyle.

Radio Zonde is a free shoot 'em up arcade-style game, made by the doujin group Inudon Empire, also known as Ruminant's Whisper, the developers of Hellsinker (and Dogma, a fighting game). It can be considered Hellsinker's spiritual predecessor, featuring similar gameplay elements and artstyle.