@adrao, well considering most customers are probably Millennials, I don’t think it’s surprising that zombies, superheroes and fantasy frequently sell well. That being said, I think you still need to make “the genre your own” when writing, even in a popular genre.
Some genres are more geared to older audiences. Historical romance, for example, might appeal more to women in their 30s/40s. Military fiction/Tom Clancy stuff, appeals more to middle-aged men. I know many friends my age who enjoy true crime stories and gritty stuff like that. That’s not to say that Millennials can’t like those genres; it’s probably just a harder sell.
I do think that some CoGs are hard to categorize or might straddle different genres. That’s not a bad thing at all, but it makes it a bit harder to describe.
EDITED TO ADD: And regarding the whole “free to sample” approach; I think it DOES result in more 1-star reviews, BUT, I think it also results in MORE sales, because you’re getting people past that initial price barrier. Some of them will enjoy the sample enough to justify them buying the game, when they may never have risked buying it sight unseen. Those people may be giving you 4-star and 5-star reviews (that you never would have gotten without the free sample), but they rarely include “I tried this for free and liked it enough to buy it!” in their reviews. Some will say that, but most won’t.