I'm honestly a sucker for the Harvest Moon series. I was skeptical about the Rune Factory games, but a pair of my friends enjoyed the first one well enough that I grabbed the second during a Black Friday sale at Amazon.
One of the main differences between it and traditional Harvest Moon games is the use of quests. Or, rather, requests, as they are called in game. As people begin to like you more, they will post requests on the billboard for you to carry out (there are also some that are not, in any way, related to how much they like you). This is typically how you get girls to like you.
The main problem is that everything is a small fetch quest, and not even an interesting one. Most of the time you're just running from one end of town to the other. Early on some of the quests try and teach you about different aspects of the game, but they don't really do it in an interesting manner.
Even so, it is still one of the more interesting parts of the game. It's just a shame that Natsume doesn't have a better writing staff to create more interesting quests and characters. Still, it shows the potential for combining Harvest Moon with other genres to a rather pleasant effect.