Assume that somebody made a high-budgeted big-profile video game where the player takes control of one or more Nazi officers in the Auschwitz concentration camp in 1942, and is tasked with handling the prisoners, with everything that it entailed, including the mass extermination part. This game would be completely "neutral" in the sense that it simply would depict the day-to-day duties of such officers in a very realistic manner, and there would be no political or ideological message, no "preaching". There would be no happy ending. (The game could end, for example somewhere around 1943, when the camp was still in full operation.)
Such a game would cause an outrage. Morality guardians, the media, and basically everybody would be all over it, classifying it as the worst thing that has ever come out of the gaming industry.
This kind of depiction (especially if neutral, like described above) is in fact more or less "allowed" for other forms of media, such as literature and film. Such a book or film, if well done, would be described as a gritty and harsh depiction of historical reality. Even if the work is not "preachy" nor tries to hammer down some kind of lesson or political idea, it would still be considered to be teaching some kind of lesson implicitly.
This is allowed for other forms of media even with non-historical, ie. completely fictional depictions of brutality and injustice. In other words, even if the work of art doesn't have the excuse of depicting actual history, but it's all completely fictional, it's still allowed (especially if it's well made.)
But not so with video games. For some reason video games are held to much, much stricter standards of political correctness.
To be fair, there is some leeway. There are some games where the player controls a criminal, and there is no punishment for said criminal at the end, nor any kind of preachy message that crime is bad. The Grand Theft Auto series would be the quintessential example. However, said series (and the other few similar games in existence) have come under heavy criticism from moral guardians. Much more so than any movie or book with similar depictions (which exist aplenty.) Heck, some books and movies that depict criminal life in a completely non-preachy manner are considered some of the best books and movies ever made.
But while there is a bit of leeway with games like Grand Theft Auto, a game like the one I described at the beginning would never fly. It would cause enormous amount of controversy. So much, in fact, that I don't think any game company of any recognition would dare make such a game in a million years.
Sometimes these heightened standards for video games in particular go to ridiculous lengths.
For example in Germany depicting the Nazi swastika is forbidden by law, except in historical books and films. With the exception of, you guessed, video games. In video games it's forbidden period, regardless of how historically accurate the game might be, or what the context of using the symbol is. It doesn't make any difference.
Recently Apple pulled out of their App Store all games depicting the Confederate flag, with the argument that it's "racist." This included all the American civil war games. Again, historical accuracy and context have no bearing on whether the game was pulled. And, most egregiously, Apple announced very explicitly that they are doing this with games only; they very explicitly stated that making political statements, using all kinds of symbols etc. is completely ok and allowed in their digital book store and in movies, but not in their app store. They quite explicitly stated that games are held to a different standard than books and movies.
That's completely right: You can publish a book with the Confederate flag on the cover in Apple's digital bookstore, even if the book endorses the use of the flag or the politics behind it, but you are not allowed to publish a video game of, for example, the American civil war, if it contains the Confederate flag within it, completely regardless of the context or what the message (if any) of the game is.
This is completely silly. Why are video games held to a different standard than other forms of media? Why the double standard?