This game is not nearly as bad as the reviews suggest but it's definitely something you should read up on before you buy--if you blindly expect it to be similar to recent HM games (and why wouldn't you?) you'll be sorely disappointed, as it omits or moves away from a lot of modern HM tropes that people take for granted, but it's not terrible by any means and it could become a genuinely good series if they make an effort to listen to fan feedback.
So Harvest Moon fans should follow the Story of Seasons games and ignore these new Harvest Moon ones, right?
If your interest is primarily in the romance/relationship aspect, yeah, stick with Story of Seasons (or Rune Factory), without a doubt. Lost Valley is a farming game, through and through.