They're all selectable. Unless you mean when you're posting a download, in that case I don't know if you can still select them. Either way, they could just move the ones in outdated categories to the other ones.
An idea too, what about using some sort of picture instead of the tiny text at the top. Like maybe a small screen of a standout game in that genre with the category name next to it. Or I'd be willing to make some sort of icons to put up there.
Edit: After checking out the interactive fiction category and realizing there's only 1 game in it, it could probably be done away with . . . just move that game to "adventure" or "other"