Fantasy, superhero, and romance, no doubt. Oh, and school stories, of course. There are a lot of games in those genres and many of them are quite successful. Of course, the fact that there are fewer games in e.g. science fiction, sports, or historical only means that the readers who want those games are much more eager when a new one comes out. If you write a good game in a less-popular genre, it’s very likely to find a small, but dedicated, audience.
