Ragnagard, sometimes known as Operation Ragnagard and known in Japan as Shin-Oh-Ken (神凰拳, lit. "God Phoenix Fist"?), is 2D arcade fighting game developed by Saurus and published by System Vision for the Neo-Geo arcade, Neo-Geo CD and Sega Saturn. Unlike the arcade version, in which the player could play as one of the bosses by entering a cheat code, the Sega Saturn version allowed the player to play as the bosses by just entering the versus mode.
Source: Wikipedia, "Ragnagard", available under the CC-BY-SA License.