Stardew Valley's love interests are great as they are, but more wouldn't hurt. The game has a wonderful selection of marriage candidates, but it's never too late to add more to the roster. While mods can do this too, it would be fun to see in-game expansions as well. Stardew Valley tends to focus on romantic tropes and then flesh them out as real people when it comes to creating love interests, and this would be a good chance to either add new ones or make existing NPCs dateable.