• LGBT characters
• Slavery and the bravery the slaves had
• Victims of racism and their story
• Victims of violent attacks because of who they are or what they believe in

As Tom pointed out, the primary goal of publishers in general is making a profit from the game. And it tends to be that the first things to push those new ideas fail miserably; and that's just the price to be paid with raising social awareness. It virtually never happens overnight.

If you believe in the cause strongly enough that you're willing to risk your money publishing the game, the sky is the limit (or more aptly, the law is the limit) for what causes you bring attention to. If you're not willing to take on that financial risk, then you're stuck where so many developers are... having to balance providing enough "standard fare" for the genre you're in while using some smaller portions of your game to create awareness.

As for sugar-coating, I think mainstream games sugar coat to a level similar to mainstream movies and mainstream tv. It's arguable if that's pushing the envelope far enough, but I think that it's pretty in-line with what you should expect. The investors put their money into the companies for a return on that investment. If they want to raise social consciousness, they donate money to a charity that pushes that cause.

As for playing a game that has controversy, I have no desires or complaints regarding it. I played that Call of Duty that had you play as a terrorist in an airport. I had already bought the game and was in the middle of the story before I heard that the mission existed. I don't think that controversial mission would have prompted me to buy the game if I hadn't already. And it didn't cause me to take the game back since I already had it. If your game was good, controversy aside, I think that's a good first step to getting people interested enough to play your game (and be influenced by your cause).

That's why writing for games isn't very highly rated, I think you have got a point and the competition to provide 'shocking' content is getting sleazy and boring. A bit like seeing a shark sawn in half, seen one and you've seen em all. So yeah perhaps you could make your game have a friendly character from the opposite faction, (friendly orc, troll, ogre, dog, spider, goblin, zombie (Gollum is one, however he is a traitor), ring wraith, ghost.... etc). And you could use the story of that character to explore those issues. The trick is that you need to incorporate the themes into your design (was the film called green mile?, and Sintel the open movie actually goes into great thematic depth) and keep the normal look'n'feel, so perhaps you are considering an extreme art pipeline and a great orchestral music setup ... then I think most of what you want to do has been done before in various limited ways.

Its funny you should mention this because I've been thinking the same thing as of late. And in my game I'm planning to address some of these. There will be rape, slavery, etc etc...

Skipping what you consider sugarcoating a game does not necessarily make the game better, as the contents might be overshadowed by the "triggering stuff". When you write for a game or movie you cherry pick elements from reality or a story and enhance their features/aspects to make sure the message comes through. A part of this is to reduce the impressions from unimportant things - like a triggering sex scene or excessive brutality.