Considering that at least one person will have his or her sensibilities offended by absolutely everything, there is no point in trying to avoid "harsh" topics because they might offend someone. That being said, I think not all platforms are equally suitable for such topics.
For instance, there is a wide plethora of WWII strategy games (both RTS and turn-based), but neither of them really makes you care about the people you commandeer. They're disposable units on varying battlefields. As a result, I think that a First Person shooter would be better to capture the gruesome conditions on the battlefields of WW I and WW II (especially the former, about whose trench warfare relatively few games exist).
More extreme examples such as the Holocaust or the Mass Starvation during the Chinese "Great Leap Forward" are harder to package into a game. "I have no mouth and I must scream" had one chapter that was clearly based on a concentration camp (sans the proper insignia) but had a proper border, so to speak, because the entire game revolved various forms of living nightmares. Even so, said KZ chapter was removed from the German version, making it impossible to achieve the game's good ending.