Well, the basis is the same but each game have a variation. Example: Tale of Two Towns Revolves around two Villages. One is based in Livestock, the other is based in Crops. The actual story bit of the game revolves around you restoring the friendship between the two Villages; unlocking the tunnel that connects the two. While, others are much more simplistic. The basis of Harvest Moon is Farming and Ranching, Marriage, Birth, Events, etc. I love the series because it reminds me of a Sandbox RPG, combined with Farming.