As the boss gangster introduces his crew, not only does he sound like Edgar G. Robinson, but some of the henchmen's names are similar to Reservoir Dogs, and one even looks like Steve Buscemi.
The forces that guard the Neptune Jewel, Earth Wind, and Fire, may be a reference to real-life funk band, Earth, Wind, and Fire. Earth, Wind, and Fire and American gangster Al Capone, on whom the boss gangster is based, both originated from Chicago.
The boss gangster resembles infamous American gangster, Al Capone, who operated mostly from Chicago.