I haven't had the chance to play it yet, but a stealth-based game called "Velvet Assassin" came out recently, despite the name it's supposed to be based on a true story of someone fighting back in their nation in a way other than blasting through endless waves of mindless Nazi soldiers. Like I said, I haven't played it yet, and haven't heard the story behind it, so I don't know how accurate it is, but I thought it might be relevant.
Like Fraser said, it might be difficult to convey the events that are usually just ignored in WWII game in an FPS, or anything meaningful at all for that matter. It is not, however impossible to pull off in such an FPS game. Much as it seems...odd, to bring up in a serious discussion about historical games, I find myself thinking of Bioshock, and not just because I've been wanting to play it recently. One of the things that was very much promoted when I first heard of it, alongside the plasmids and the plot, was the moral choice given the player. In the interview I read before it's release one of the developers said the Little Sisters were apparently part of an attempt to evoke emotion in the player and make the experience more memorable. It was for me, I played through the game and saved every little sister I could find, and enjoyed the "good" ending as a nice way to wrap up the game, it even almost had a "happily ever after" thing going in a sense. Then I decided to play the game through again to see the bad ending, like I usually do (in fact I usually do the bad ending first), I made my way to the first Little Sister where you are given the choice to harvest them and... I couldn't do it. Some of you may say it's just a game, and while that's true, it was something I just didn't want to do for many reasons. The little sisters are creepy to begin with, and I had never read what happens to them when you harvest them, and the term "Harvest" is horrible enough when referring to a human being, let alone a child (even though they try to dehumanize them right before so you can actually make the choice), and the term is also vague enough to force me to use my imagination, which always conjures up terrible images that are always worse than the reality, probably. To this day I haven't even seen what happens when you choose "harvest," either from playing or watching someone else play in real life or on a video on the internet, and perhaps, now that I've heard someone describe it just recently, and it doesn't sound as horrible as I thought, I will try it again. I can sit here and type about how it's just a game, but I can't forget how much that choice affected me. On the other hand, I've no idea how it impacted other people when they played the game, I'll probably be receiving one message just in response to this post telling me what a coward I am. And there's always the fact that, though it fit in well with the plot of the game, it always seemed sort of separate, like it was something they added after they finished making the game. It just felt out of place in the middle of a game where I was shooting lightning, among other things, at grotesque genetic abominations, who, while disturbing in their own right, were mostly unnamed and were not filled out as characters. Those that were given backstory, their tragic fall from humanity or sanity unveiled right before fighting them, were usually victims of their own greed, vanity, and so on, and my sympathy was further compromised by their trying to maim and kill me. In the middle of this you are given the choice about the little sisters, the moral impact of which is felt only in the moment you choose and at the end of the game. The concept did it's job, and created a memorable experience, but never really made me think other than about the consequences of the choice itself, it possibly had some sort of deep, metaphorical meaning that I completely missed, or it was a gimmicky moral choice put in to make you want to play the game at least twice. Sorry about that, my point is that an emotional experience is attainable, even if you go to great lengths to make it fit with the game's story, but there's absolutely no guarantee the player will care, and even if they do, there's also a chance they might not understand at all. In a historical themed game this might be good, since it might cause them to go find out more on their own, like a few of my classmates who were discussing just yesterday how much they had learned from a Medieval RTS they had played, either directly or indirectly.
The problem arises in the fact that any sense of plot, emotion, or moral lesson can be almost ignored by the player who just wants to shoot things, even if they were placed in the game. Anything in the gameplay environment can be easily overlooked in the middle of a hectic gun battle, and cutscenes can usually be skipped, unskippable cutscenes might cause the player to stop playing the game, get up and do something else until it is over, or just be so upset that they are being interrupted that they completely miss what's going on.
While I agree bringing the more realistic aspects of history should be at the very least mentioned in historically based games, and that developers should continues to try out new ways to make this work, so far there doesn't seem to be a clear way to put this in practice that will allow everyone to see why it's there, or in some cases, why it matters.
I played through Assassin's Creed with almost no prior knowledge about the crusades, I was vaguely aware that, at some point in medieval times, a bunch of knights went over to the middle east and started a war for some reason. The Knights Templar were slightly more important knights that got involved in a bunch of conspiracies. "Assassin" was a word for someone who stabbed someone in the back while they weren't looking, I knew the word originated from the middle eastern group that did this notoriously well, though I had heard no accounts of actual exploits of the group, and apparently they did it for religious reasons or something. Afterwards, I've learned more about the period through other sources, like my history class, and the internet articles and posts I read speculating about the sequel (before they announced it was taking place in the Renaissance and not the Crusades). But my knowledge of the period is still minimal, as is my awareness of how inaccurately it was portrayed in the game (the ending obviously hangs a question mark and how accurate the rest of it was, considering the last section is blatantly fictional).
So understanding of a game's historical accuracy and meaning also depends on the prior knowledge obtained by the player. While I have played WWII based games that do give a brief history of the events leading up to the battle, they do not cover the events outside of the actual armed conflicts just like the others you mention. The only way to guarantee that all of it was depicted would be extended historical accounts prior to playing the game, at which point you may as well sell the game packed with a DVD of a history channel show about the war and everything associated with it, since you can't confirm how much they know prior to playing it. Even then, when you've gone to such great lengths to get the whole picture into a story that people will see, there are still going to be those who are too young to understand, who will play the game anyway, possibly skipping the story in favor of multi-player gaming.
Most of it depends on the player. So while it is perfectly possible to get people to see the whole picture in one form of media, games make this difficult, and the biggest hurdle of all is the player's mindset, when someone starts up their game system looking for pure entertainment value, there's a good chance they just wont be paying attention to the history behind it.
