i have it on my DS and i have to say its pretty fun.
if you liked the Harvest Moon series then you should definately pick Rune Factory up.
Rune Factory has a small storyline (theres no time limit) and the new addition of fighting monsters and exploration.
sprites are replaced with monsters you have to befriend and mines are now replaced with caves full of monsters.
if you want more info on Rune Factory check out this site:
http://www.fogu.com/hm/rune_factory/index.php