Another version of Rage of the Dragons, this one marked with NGM-264?, indicates a variation in the original arcade release. The question mark in the code suggests a possible regional variant, an incomplete ROM, or a slightly different hardware configuration.  It's gameplay should share similarities to the NGH-2640 version, but differences may lie in graphics, sounds, or even the character roster.

Rage of the Dragons (NGM-264?)

Radical Radial (US)