Realistic naval fleet combat sims. There’s not a lot out there. I assume that there’s probably limited demand – flying fighter planes seems to be a lot more popular when it comes to military sims. Rule the Waves does keep seeing releases, but it’s not a genre with many decent entrants.
Kenshi-style games. I’m not sure that there is a name for the genre, but sandbox, open-world, squad-based combat with a base-building and economic side.