'School based' I've always assumed was meant for Harry Potter style games or else stuff like all those visual novel dating games. I've seen other sites where it gets it's own genre too, it's A Thing for some people apparently.
Sci fi I was just surprised by. I'd never really noticed the numbers before, I was just scrolling down the list and it's like wow, that's it? I'd have figured it would be up there with Fantasy in popularity.
A lot of the ones that we do have there have pretty solid rating and a good length, though, so quantity over quality is nothing to complain about.