The only thing that may put a damper on your experience is the game's over-reliance on the DS' touch screen. Everything in the game is controlled using the stylus, which works very well for precise tasks such as watering plants, playing the milking minigame or managing your inventory, but can be quite annoying when it comes to moving your character around. You'll find yourself walking when you want to run, and standing still when you want to move just a bit to the side. It's not a game-breaker, but The Escapist found themselves constantly wishing they could just use the D-pad to move around the island.
Bottom Line: Harvest Moon: Island of Happiness is the most cheerful grind you're ever likely to encounter. If you're willing to put in the time, you'll be rewarded for your efforts. Also, the cows and sheep are freakin' adorable.
Recommendation: If you're a fan of the series, there's no question you should have this game, as it adds several new satisfying tweaks to the well-worn formula. For everyone else, if you're allergic to cute or don't have much time to spare, sail on by. But if you're looking for a game you can really throw yourself into, you'll truly enjoy your time on the ranch.