Once you get used to the frustrating controls you're in for a treat.
This time around your goal is to revitalize an island with a focus on drawing new villagers (by meeting certain requirements) to the island and building upgrades such as bridges to new areas and more buildings on your farm (greenhouse, chicken coop, etc). Among those new villagers are several marriage candidates, and in addition to your farming responsibilities you get to court and marry one of them. FYI, you can choose to play as a boy or a girl in this game.
Another new feature is the addition of "wonderfuls" which are colored stones that upgrade your tools. Each color has a different effect which makes your tools more useful or easier to use. At first this makes tools tough to use because they use a lot of stamina, but once you get a wonderful collection going you'll find it much easier to complete your daily tasks.
This time around, you are able to raise up to 16 chickens and a combination of 16 cows and sheep (after upgrading your coop and barn, of course). The wonderfuls allow you to increase the amount of love points you get from using your brush (Don't forget to charge it!) and the number of milk/wool you can receive. There is also a petting mini-game you get randomly every few days which allows you to increase your animals affection for you. There's a similar mini-game for milking/shearing which allows you to increase the quality of your product.
There's much more to it, but I don't want to give away all of the secrets!
Controls: 7/10 - A bit frustrating, but they actually work really well once you get the hang of them.
Sound: 8/10 - As always, Harvest Moon has good background music, but it does get kinda repetitive after awhile, and the cicada during the summer is very annoying.
Difficulty: 7/10 - At first it is quite difficult, but once you get going it's actually pretty easy.
Replay Value: 7/10 - In previous Harvest Moon games, I find that once you accomplish most of your goals, it starts to get very repetitive. I haven't reached that point with this game yet, but I do think there's a bit more replayability than in previous versions due to the difficulty in crop growth and sheer number of animals to raise. There's also the goal of completing your shipping and recipe lists, which can prolong the experience.
Enjoyability: 9.5/10 - It's much more rewarding this time around to grow your crops successfully due to the complications of the weather, and there's a lot to do both on and off the farm.
Final Thoughts: 9/10 - Fans of the series will love this new addition, while newcomers may find the learning curve a bit higher than HMDS, but will enjoy it nonetheless. There are a lot of new features which make great additions to the series. Just be patient with the new controls!