I made an English account for my PS3 so I could download the Castlevania Demo. It clocked in at about 1.5 GB and took me about 12 or 15 minutes to beat... so I'm not sure why it was so short...
I liked what I played, but these kind of games tend to not demo very well, in my opinion. I'm hoping to like the full game- when I get around to playing it in 6 to 8 months. ;)
EDIT: Bah! Now the Castlevania demo is on 360 for everybody... so much for being sneaky.