Are you really a fan of the series?
Most of the reviews made me not want to play the games, especially the GBA and NDS ones, which you made look really bad.
You made the PS2 ones seem worth it just for the soundtrack. You praise the Lords of Shadows series, but they don't seem to be masterpieces. You don't even make Symphony of the Night, which other fans say is a masterpiece, seem like a big deal.
From what I understand from my reading, Castlevania III was the great game and nothing that came after is as good.
For a book made by a fan I found the criticism quite harsh.
I played some of 8bit and 16bit games and I found them quite good, but after reading this book, I'm not interested in playing the rest of the franchise.