Complete Monster: Monroe Feather is a ruler of a Neo-Nazi organization who despises anyone who isn't white, but Feather harbors a special fury and loathing for African-Americans. He puts a Mad Scientist to work devising a sinister toxin that will only affect African-Americans and wipe out every black person in Washington D.C., Detroit and L.A. when it is placed in the water supply. After this is done, he plan to take the genocide global. Motivated by nothing more than hatred, Feather is one of the most vile and memorable villains in Blaxploitation history.
Tropes that pertain to the video game
What Do You Mean, It's Not Political?: Duke Salem and Duke Greene could easily be seen as representations the US Democratic and Republican parties (complete with Greene making threats about seceding to form his own nation, though Texas' real life threats of secession weren't as well-known until years after the game was made.) Salem is even explicitly referred to as liberal. Duke Greene being pretty much unambiguously evil could push this into Anvilicious territory.