Pseudo-Philosophical-Moral-Psychological Themes in games were people don't know anything about, e.g. Nier 1, Nier 2, The Last of Us, Life is Strange et cetera. They are ALL great games (Nier 1 is my 2nd favourite thing of all time after all) but for the last few years that usage has come to an overkill. Bring in some bits and pieces, fine. But don't force it.