How to play Zoku Satsuriku no Django: Jigoku no Shoukinkubi on Mac

The planet Sweetwater is a wasteland of burning desert sands, an abandoned utopia of thieves where the usage of galactic technology is strictly forbidden by advanced bio-mechanical lifeforms known as Protozoans who watch over the planet from the skies above. Here, a single legend is uttered with equal reverence betwixt the ranks of the corrupt nobility, the downtrodden farming peasants, and the bloodthirsty rogues who make Sweetwater their nest - this is the legend of Black Franco, a gunslinger-cum-revolutionary who managed to amass a hidden fortune, incite a revolution, and earn a 500000 dollar price on his head before vanishing ten years ago. Recently, however, there have been new rumors of a gunslinger appearing with Franco's trademark gun, the Black Hawk, in hand... Lily Salvatana, a particularly sagacious headhunter, takes it upon herself to claim the massive bounty set on Franco's head. However, Lily soon encounters a mysterious gunslinger who refuses to speak her name who seems to have the same idea - exactly who will end up claiming the bounty? And in the first place, who exactly is Franco?