I've only read pieces of the ebook so far, as I've mostly been playing the games, but I was really struck by how many good ideas were left on the table, especially with Super Castlevania IV. It looks like some of these concepts were absorbed into Rondo of Blood (burning city, canoe ride) and some were put into Bloodlines (rotating tower you climb), but there's still more left, like the levee bridges. And some of these ideas, like the canoe ride, seemed more involved than what Rondo did with it. Plus, interesting that you originally could wrap the whip around some enemies and toss them aside! The creativity and passion oozing from these documents is amazing. It wasn't about just making "another" Castlevania; it seems each time it was about pushing the limits of innovation and appropriateness for whatever hardware a given game was to come out on. Curiously, though, the Super Castlevania IV document ideas do seem to resonate with Super Ghouls N Ghosts' concepts with the tower and water levels. Also, we learned that the spinning room is actually a mechanized chamber created by Dracula, and not some illusion.