Gun Frontier

Gun Frontier is a 1990 arcade vertical shoot-'em-up developed by Taito. Taking place on the planet gloria, a newly colonised planet with a manner of living similar to that of the american west, the player fights to defend settlers from airborne pirates, many of which are shaped after guns of the old west. 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.