Picked up Xenosaga ep. 1 about 4 years ago... and I still haven't finished it. I got stuck at the part where you fight the skeleton boss that splits into two (? I dunno, I haven't played in a long time...haha)- but I didn't have high enough levels and saved in a spot where its hard to level up.
Never had the motivation to start over, though...
Apparently it's a hit or miss game, people either seem to love it or hate it.