Worst Port Ever? Yeah.
The only good you get from this game is the ability to marry Lumina, one of four (three for the regular AWL) cute brides for this game. Not only does this game lag heavily, the graphics and textures are horrible, the game is too dark, the text is smaller and suddenly appears on screen, all the music has changed, and it uses a sticky camera system.
Aside from the negative, you change your clothes depending on the season, you don't just start out with all your fields or anything like that, and some of the characters have new looks. (Nami, for instance.)
Harvest Moon simply wasn't made for the PS2, or perhaps Natsume simply needs to try harder? Either way, I give this game a generous 6/10. It's more of a collector's item for the die hard Harvest Moon fan.