Looking at how minorities were treated during and after the war

(Ref taken from https://www.bbc.co.uk/bitesize/guides/zqrfj6f/revision/4)

(Ref taken from https://hmd.org.uk/learn-about-the-holocaust-and-genocides/the-holocaust/nazi-persecution-of-the-jews/)
How I can convey it in my universe:

‘Untermensch’ being used as a racist slur in Nazi Germany, could make a good name for a character in my game maybe a companion that could switch forms.
Why base my game would tackle serious real life themes, my main vision was to create this fictional world to explore and lighten the heavy subject based around World War 2. Personally having experience with growing up in a household largely defensive about the Jewish ethnicity and the trauma that happened in 1945 I felt like it was silenced rather than explored. My interest of asking the question of what the world would look like if the Nazis won, however I did not want to offend or make my game too dark rather make it funny as well and how I find a humorous side in it while still showing the actual suffering and horrors the Nazis inflicted, maybe through posters and bodies scattered across each level. Additionally, for individuals who have experienced trauma or experienced a close member to them have it, I wanted to make them laugh and lighten their heavy past by using silly characters and music to almost a coping mechanism through killing hordes of Nazis.
My families history in the Second World War
My father’s great grandmother in the 1940’s Soviet Union sent her children away to flee to the forest before being caught and killed. Most of her children died before they managed to reach the non Nazi annexed territories while her son (my great grandfather) managed to escape and enrol in the Soviet’s Union’s army where he met his brother and whom they both survived and eventually moved to Israel.
My mother’s grandfather managed to migrate to Uruguay after the Nazi regime came to power, however not everyone in his family had the same fate and his parents died from unknown but most likely killed by the Nazis.