Both Mach Rider's identity and gender are ambiguous. They are portrayed with a muscular build, and the NES and Famicom versions' manuals never use any gendered pronouns to refer to them. The arcade port Vs. Mach Rider's stage clear screens slowly introduce piece-by-piece an image of a skimpily-dressed woman (bearing similarities to Jane Fonda's appearance in the 1968 film Barbarella) holding a dagger, but it is never specified if this character is Mach Rider, or one of the other wasteland survivors. However, Mach Rider's trophy description in Super Smash Bros. Melee years later lists them as a male character with he/him pronouns. Even later on, Captain Rainbow, a game centered around obscure and neglected Nintendo heroes, has an unused model for Mach Rider that, while not having visible breasts due to wearing armor, portrays them with a feminine skinny waist.