I don't know whether to get this or not... I'd love to wait till the price drops to 20$, but CV's always get insanely hard to find after a while.
I'm a little disappointed to hear it's more linear. The entire reason I love Castlevania is because of the exploration. If Nintendo wasn't going to make Metroid's anymore I would depend on IGA to make it.
It really isn't any less linear than the previous couple of games if you were to get rid of the level map and put everything together. There are still areas in levels you can't get to initially and have to return to with the right power-up, with passageways leading back to the beginning of the level, and all that jazz. There is really no difference in having a map to select levels or going through portraits/finding new areas in a castle other than the convenience of not having to backtrack across the castle map (or warp).
And it IS more difficult, but still a bit on the easy side so far. The second major boss killed me a few times until I found out how to dodge his attack pattern; after that I never got hit once.
Really I think this game needs some pitfalls and more traps. If you're going for a more linear level design, PUT SOME DAMN HOLES IN THE GROUND. It just feels too easy most of the time.