I've also played Castlevania: Portrait of Ruin, FF3, FF4, and several other DS games for a lot longer than that, only including the main story. I've probably played Contact longer than that, and I'm only halfway through.
Still though, considering these are DS games, 24 hours of gameplay or more is pretty impressive for such a little cartidge, but I guess that's to be expected with most RPGs.
Oh, and what's Contac like? I've heard it's kind of like Earthbound, or Mother or whatever.