Gun Frontier is a 1990 arcade vertical shoot-'em-up based on the animated series of the same name. The setting of the series and purportedly of the game is an extraterrestrial American Wild West, with the player fighting to defend settlers from airborne pirates -- the game, though, actually looks to be an entirely standard military-themed shooter, with the player's jet fighter set against tanks and other airplanes. Guns and bombs are levelled-up and collected by dropped power-ups, which are money-themed, with the gun upgrades shown as American dimes and bombs as gold bars.